Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Sn(CO2)2”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Sn(CO2)2 by Materials Project

SnC2O4 crystallizes in the monoclinic C2/c space group. The structure is one-dimensional and consists of two SnC2O4 ribbons oriented in the (1, 0, 1) direction. Sn2+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (2.27 Å) and two longer (2.41 Å) Sn–O bond lengths. C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.26 Å) and one longer (1.28 Å) C–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Sn2+ and one C3+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sn2+ and one C3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SnMoH6(CO2)2 by Materials Project

MoSnH6(CO2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mo6+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with four equivalent SnC2O4 octahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of Mo–O bond distances ranging from 1.77–1.81 Å. Sn4+ is bonded to two C4- and four O2- atoms to form SnC2O4 octahedra that share corners with four equivalent MoO4 tetrahedra. There are one shorter (2.12 Å) and one longer (2.13 Å) Sn–C bond lengths. There are a spread of Sn–O bond distances ranging from 2.14–2.57 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Sn4+ and three H1+ atoms. All C–H bond lengths are 1.09 Å. In the second C4- site, C4- is bonded in a distorted trigonal non-coplanar geometry to one Sn4+ and three H1+ atoms. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C4- atom. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Mo6+ and one Sn4+ atom. In the second O2- site, O2- is bonded in a linear geometry to one Mo6+ and one Sn4+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to one Mo6+ and one Sn4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li4V3Co2Sn3O16 by Materials Project

Li4V3Co2Sn3O16 is Hausmannite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three VO6 octahedra, corners with three equivalent CoO6 octahedra, and corners with four SnO6 octahedra. The corner-sharing octahedra tilt angles range from 56–68°. There are a spread of Li–O bond distances ranging from 1.99–2.07 Å. In the second Li1+ site, Li1+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.81–2.05 Å. In the third Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share a cornercorner with one VO6 octahedra, corners with two SnO6 octahedra, corners with three equivalent CoO6 octahedra, an edgeedge with one VO6 octahedra, and an edgeedge with one SnO6 octahedra. The corner-sharing octahedra tilt angles range from 58–62°. There are a spread of Li–O bond distances ranging from 1.80–2.00 Å. In the fourth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three VO6 octahedra, corners with three equivalent CoO6 octahedra, and corners with five SnO6 octahedra. The corner-sharing octahedra tilt angles range from 56–64°. There are a spread of Li–O bond distances ranging from 1.98–2.12 Å. There are three inequivalent V+4.67+ sites. In the first V+4.67+ site, V+4.67+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with three LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one CoO6 octahedra, and edges with four SnO6 octahedra. The corner-sharing octahedra tilt angles range from 48–51°. There are a spread of V–O bond distances ranging from 1.88–2.05 Å. In the second V+4.67+ site, V+4.67+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of V–O bond distances ranging from 1.74–2.01 Å. In the third V+4.67+ site, V+4.67+ is bonded to six O2- atoms to form distorted VO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with three LiO4 tetrahedra, an edgeedge with one CoO6 octahedra, edges with two equivalent SnO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 48–50°. There are a spread of V–O bond distances ranging from 1.75–2.35 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form distorted CoO6 octahedra that share corners with two equivalent VO6 octahedra, corners with two equivalent SnO6 octahedra, corners with three equivalent LiO4 tetrahedra, corners with three equivalent LiO4 trigonal pyramids, an edgeedge with one VO6 octahedra, and edges with two SnO6 octahedra. The corner-sharing octahedra tilt angles range from 48–56°. There are a spread of Co–O bond distances ranging from 2.10–2.35 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form distorted CoO6 octahedra that share corners with two equivalent VO6 octahedra, corners with four SnO6 octahedra, corners with three equivalent LiO4 tetrahedra, an edgeedge with one VO6 octahedra, and an edgeedge with one SnO6 octahedra. The corner-sharing octahedra tilt angles range from 48–58°. There are a spread of Co–O bond distances ranging from 2.11–2.38 Å. There are three inequivalent Sn+3.33+ sites. In the first Sn+3.33+ site, Sn+3.33+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with three LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one CoO6 octahedra, edges with two equivalent VO6 octahedra, and edges with two equivalent SnO6 octahedra. The corner-sharing octahedra tilt angles range from 54–58°. There are a spread of Sn–O bond distances ranging from 2.06–2.13 Å. In the second Sn+3.33+ site, Sn+3.33+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with three LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one CoO6 octahedra, edges with two equivalent VO6 octahedra, and edges with two equivalent SnO6 octahedra. The corner-sharing octahedra tilt angles range from 55–58°. There are a spread of Sn–O bond distances ranging from 2.08–2.11 Å. In the third Sn+3.33+ site, Sn+3.33+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with three LiO4 tetrahedra, an edgeedge with one CoO6 octahedra, edges with two equivalent VO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 54–56°. There are a spread of Sn–O bond distances ranging from 2.07–2.14 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one V+4.67+, one Co2+, and one Sn+3.33+ atom. In the second O2- site, O2- is bonded to one Li1+, one Co2+, and two Sn+3.33+ atoms to form distorted OLiCoSn2 tetrahedra that share corners with three OLiVSn2 tetrahedra and an edgeedge with one OLiVCoSn tetrahedra. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one V+4.67+, and two Sn+3.33+ atoms. In the fourth O2- site, O2- is bonded to one Li1+, one V+4.67+, and two Sn+3.33+ atoms to form distorted corner-sharing OLiVSn2 tetrahedra. In the fifth O2- site, O2- is bonded to one Li1+, two V+4.67+, and one Sn+3.33+ atom to form distorted corner-sharing OLiV2Sn tetrahedra. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one V+4.67+, one Co2+, and one Sn+3.33+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, one V+4.67+, one Co2+, and one Sn+3.33+ atom. In the eighth O2- site, O2- is bonded to one Li1+, one V+4.67+, one Co2+, and one Sn+3.33+ atom to form a mixture of distorted edge and corner-sharing OLiVCoSn tetrahedra. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Co2+, and two Sn+3.33+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one V+4.67+, and one Co2+ atom. In the eleventh O2- site, O2- is bonded to one Li1+, one V+4.67+, one Co2+, and one Sn+3.33+ atom to form distorted corner-sharing OLiVCoSn tetrahedra. In the twelfth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one V+4.67+, one Co2+, and one Sn+3.33+ atom. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, two V+4.67+, and one Sn+3.33+ atom. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one V+4.67+, one Co2+, and one Sn+3.33+ atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, two V+4.67+, and one Co2+ atom. In the sixteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one V+4.67+, one Co2+, and one Sn+3.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co4SnSb12 by Materials Project

Co4SnSb12 crystallizes in the cubic Im-3 space group. The structure is three-dimensional. Co2+ is bonded to six equivalent Sb1- atoms to form CoSb6 octahedra that share corners with six equivalent CoSb6 octahedra and faces with two equivalent SnSb12 cuboctahedra. The corner-sharing octahedral tilt angles are 52°. All Co–Sb bond lengths are 2.56 Å. Sn4+ is bonded to twelve equivalent Sb1- atoms to form SnSb12 cuboctahedra that share faces with eight equivalent CoSb6 octahedra. All Sn–Sb bond lengths are 3.38 Å. Sb1- is bonded in a 2-coordinate geometry to two equivalent Co2+ and one Sn4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Hidden Local Symmetry Breaking in a Kagome-Lattice Magnetic Weyl Semimetal

Exploring the relationship between intriguing physical properties and structural complexity is a central topic in studying modern functional materials. Co 3 Sn 2 S 2 , a newly discovered kagome-lattice magnetic Weyl semimetal, has triggered intense interest owing to the intimate coupling between topological semimetallic states and peculiar magnetic properties. However, the origins of the magnetic phase separation and spin glass state below T C in this ordered compound are two unresolved yet important puzzles in understanding its magnetism. Here, we report the discovery of local symmetry breaking surprisingly co-emerges with the onset of ferromagnetic order in Co 3 Sn 2 S 2 , by a combined use of neutron total scattering and half-polarized neutron diffraction. An anisotropic distortion of the cobalt kagome lattice at the atomic/nano level is also found, with distinct distortion directions among the two Co1 and four Co2 atoms. The mismatch of local and average symmetries occurs below T C , indicating that Co 3 Sn 2 S 2 evolves to an intrinsically lattice disordered system when the ferromagnetic order is established. The local symmetry breaking with intrinsic lattice disorder provides new understanding of the puzzling magnetic properties. Our density functional theory (DFT) calculation indicates that the local symmetry breaking is expected to reorient local ferromagnetic moments, unveiling the existence of the ferromagnetic instability associated with the lattice instability. Furthermore, DFT calculation unveils that the local symmetry breaking could affect the Weyl property by breaking the mirror plane. In conclusion, our findings highlight the fundamentally important role that the local symmetry breaking plays in advancing our understanding on the magnetic and topological properties in Co 3 Sn 2 S 2 , which may draw attention to explore the overlooked local symmetry breaking in Co 3 Sn 2 S 2 , its derivatives and more broadly in other topological Dirac/Weyl semimetals and kagome-lattice magnets.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on Co10SnSb30 by Materials Project

Co10SnSb30 is Skutterudite-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are six inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six Sb+0.80- atoms to form CoSb6 octahedra that share corners with six CoSb6 octahedra and faces with two equivalent SnSb12 cuboctahedra. The corner-sharing octahedral tilt angles are 53°. There are two shorter (2.54 Å) and four longer (2.55 Å) Co–Sb bond lengths. In the second Co2+ site, Co2+ is bonded to six Sb+0.80- atoms to form CoSb6 octahedra that share corners with six CoSb6 octahedra and a faceface with one SnSb12 cuboctahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are three shorter (2.54 Å) and three longer (2.55 Å) Co–Sb bond lengths. In the third Co2+ site, Co2+ is bonded to six Sb+0.80- atoms to form corner-sharing CoSb6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are one shorter (2.54 Å) and five longer (2.55 Å) Co–Sb bond lengths. In the fourth Co2+ site, Co2+ is bonded to six Sb+0.80- atoms to form CoSb6 octahedra that share corners with six CoSb6 octahedra and faces with two equivalent SnSb12 cuboctahedra. The corner-sharing octahedral tilt angles are 53°. There are one shorter (2.54 Å) and five longer (2.55 Å) Co–Sb bond lengths. In the fifth Co2+ site, Co2+ is bonded to six Sb+0.80- atoms to form corner-sharing CoSb6 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are two shorter (2.54 Å) and four longer (2.55 Å) Co–Sb bond lengths. In the sixth Co2+ site, Co2+ is bonded to six equivalent Sb+0.80- atoms to form corner-sharing CoSb6 octahedra. The corner-sharing octahedral tilt angles are 53°. All Co–Sb bond lengths are 2.55 Å. Sn4+ is bonded to twelve Sb+0.80- atoms to form SnSb12 cuboctahedra that share faces with eight CoSb6 octahedra. There are a spread of Sn–Sb bond distances ranging from 3.36–3.39 Å. There are sixteen inequivalent Sb+0.80- sites. In the first Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two Co2+ and one Sn4+ atom. In the second Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two Co2+ atoms. In the third Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two Co2+ atoms. In the fourth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two Co2+ atoms. In the fifth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two Co2+ and one Sn4+ atom. In the sixth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two Co2+ and one Sn4+ atom. In the seventh Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two Co2+ and one Sn4+ atom. In the eighth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two Co2+ atoms. In the ninth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two Co2+ atoms. In the tenth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two equivalent Co2+ and one Sn4+ atom. In the eleventh Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two equivalent Co2+ atoms. In the twelfth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two equivalent Co2+ atoms. In the thirteenth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two equivalent Co2+ and one Sn4+ atom. In the fourteenth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two equivalent Co2+ and one Sn4+ atom. In the fifteenth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two equivalent Co2+ atoms. In the sixteenth Sb+0.80- site, Sb+0.80- is bonded in a 2-coordinate geometry to two equivalent Co2+ and one Sn4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co5Sn(BO5)2 by Materials Project

Co5Sn(BO5)2 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. there are five inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with two equivalent SnO6 octahedra, an edgeedge with one SnO6 octahedra, and edges with seven CoO6 octahedra. The corner-sharing octahedral tilt angles are 18°. There are a spread of Co–O bond distances ranging from 2.03–2.31 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form distorted CoO6 octahedra that share corners with three CoO6 octahedra, edges with two equivalent SnO6 octahedra, and edges with four CoO6 octahedra. The corner-sharing octahedra tilt angles range from 52–66°. There are a spread of Co–O bond distances ranging from 1.90–2.35 Å. In the third Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share a cornercorner with one CoO6 octahedra, corners with two equivalent SnO6 octahedra, and edges with six CoO6 octahedra. The corner-sharing octahedra tilt angles range from 62–65°. There are a spread of Co–O bond distances ranging from 1.97–2.27 Å. In the fourth Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with two CoO6 octahedra, edges with two equivalent SnO6 octahedra, and edges with four CoO6 octahedra. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Co–O bond distances ranging from 1.95–2.32 Å. In the fifth Co2+ site, Co2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedra tilt angles range from 18–66°. There are a spread of Co–O bond distances ranging from 2.05–2.22 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.39 Å) and one longer (1.40 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.37 Å) and two longer (1.41 Å) B–O bond length. Sn4+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with four CoO6 octahedra, edges with two equivalent SnO6 octahedra, and edges with five CoO6 octahedra. The corner-sharing octahedra tilt angles range from 18–62°. There are a spread of Sn–O bond distances ranging from 2.09–2.14 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded to five Co2+ atoms to form distorted OCo5 square pyramids that share corners with two equivalent OCo3Sn2 square pyramids, corners with three OCo4 tetrahedra, edges with three OCo5 square pyramids, and an edgeedge with one OCo4 tetrahedra. In the second O2- site, O2- is bonded to three Co2+ and two equivalent Sn4+ atoms to form OCo3Sn2 square pyramids that share corners with two equivalent OCo5 square pyramids, corners with three OCo4 tetrahedra, edges with three OCo5 square pyramids, and an edgeedge with one OCo2Sn2 tetrahedra. In the third O2- site, O2- is bonded to four Co2+ atoms to form distorted OCo4 tetrahedra that share corners with three OCo5 square pyramids, corners with three OCo4 tetrahedra, and an edgeedge with one OCo5 square pyramid. In the fourth O2- site, O2- is bonded to two Co2+ and two equivalent Sn4+ atoms to form OCo2Sn2 tetrahedra that share corners with three OCo5 square pyramids, corners with three OCo4 tetrahedra, and an edgeedge with one OCo3Sn2 square pyramid. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Co2+ and one B3+ atom. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Co2+ and one B3+ atom. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Co2+ and one B3+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Co2+, one B3+, and one Sn4+ atom. In the ninth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Co2+ and one B3+ atom. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Co2+, one B3+, and one Sn4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li4Cr3Co3(SnO8)2 by Materials Project

Li4Cr3Co3(SnO8)2 is Spinel-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three equivalent SnO6 octahedra, corners with four CrO6 octahedra, and corners with five CoO6 octahedra. The corner-sharing octahedra tilt angles range from 55–64°. There are a spread of Li–O bond distances ranging from 1.91–2.09 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share a cornercorner with one CrO6 octahedra, corners with two CoO6 octahedra, corners with three equivalent SnO6 octahedra, an edgeedge with one CoO6 octahedra, and edges with two CrO6 octahedra. The corner-sharing octahedra tilt angles range from 61–66°. There are a spread of Li–O bond distances ranging from 1.80–1.96 Å. In the third Li1+ site, Li1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Li–O bond distances ranging from 1.82–1.93 Å. In the fourth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three equivalent SnO6 octahedra, corners with four CoO6 octahedra, and corners with five CrO6 octahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Li–O bond distances ranging from 1.92–2.11 Å. There are three inequivalent Cr+4.67+ sites. In the first Cr+4.67+ site, Cr+4.67+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with two equivalent SnO6 octahedra, corners with three LiO4 tetrahedra, an edgeedge with one SnO6 octahedra, edges with two equivalent CrO6 octahedra, edges with two equivalent CoO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Cr–O bond distances ranging from 1.91–2.01 Å. In the second Cr+4.67+ site, Cr+4.67+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with two equivalent SnO6 octahedra, corners with three LiO4 tetrahedra, an edgeedge with one SnO6 octahedra, edges with two equivalent CrO6 octahedra, edges with two equivalent CoO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 53–55°. There are a spread of Cr–O bond distances ranging from 1.99–2.03 Å. In the third Cr+4.67+ site, Cr+4.67+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with two equivalent SnO6 octahedra, corners with three LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one SnO6 octahedra, and edges with four CoO6 octahedra. The corner-sharing octahedra tilt angles range from 55–56°. There are a spread of Cr–O bond distances ranging from 2.00–2.03 Å. There are three inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with two equivalent SnO6 octahedra, corners with three LiO4 tetrahedra, an edgeedge with one SnO6 octahedra, edges with four CrO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Co–O bond distances ranging from 1.93–1.99 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with two equivalent SnO6 octahedra, corners with three LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one SnO6 octahedra, edges with two equivalent CrO6 octahedra, and edges with two equivalent CoO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Co–O bond distances ranging from 1.92–1.98 Å. In the third Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with two equivalent SnO6 octahedra, corners with three LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one SnO6 octahedra, edges with two equivalent CrO6 octahedra, and edges with two equivalent CoO6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Co–O bond distances ranging from 1.88–1.96 Å. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with two equivalent CrO6 octahedra, corners with four CoO6 octahedra, corners with three equivalent LiO4 tetrahedra, an edgeedge with one CoO6 octahedra, and edges with two CrO6 octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Sn–O bond distances ranging from 2.04–2.18 Å. In the second Sn4+ site, Sn4+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with four CrO6 octahedra, corners with three equivalent LiO4 tetrahedra, corners with three equivalent LiO4 trigonal pyramids, an edgeedge with one CrO6 octahedra, and edges with two CoO6 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Sn–O bond distances ranging from 2.06–2.18 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Cr+4.67+, one Co2+, and one Sn4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, two Cr+4.67+, and one Sn4+ atom. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, two Cr+4.67+, and one Co2+ atom. In the fourth O2- site, O2- is bonded to one Li1+, two Cr+4.67+, and one Co2+ atom to form distorted corner-sharing OLiCr2Co tetrahedra. In the fifth O2- site, O2- is bonded to one Li1+, one Cr+4.67+, and two Co2+ atoms to form distorted corner-sharing OLiCrCo2 tetrahedra. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Cr+4.67+, one Co2+, and one Sn4+ atom. In the seventh O2- site, O2- is bonded to one Li1+, one Cr+4.67+, one Co2+, and one Sn4+ atom to form distorted OLiCrCoSn tetrahedra that share corners with three OLiCr2Co tetrahedra and an edgeedge with one OLiCrCoSn tetrahedra. In the eighth O2- site, O2- is bonded to one Li1+, one Cr+4.67+, one Co2+, and one Sn4+ atom to form distorted OLiCrCoSn tetrahedra that share corners with three OLiCr2Co tetrahedra and an edgeedge with one OLiCrCoSn tetrahedra. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, two Cr+4.67+, and one Sn4+ atom. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Co2+, and one Sn4+ atom. In the eleventh O2- site, O2- is bonded to one Li1+, one Cr+4.67+, one Co2+, and one Sn4+ atom to form distorted OLiCrCoSn tetrahedra that share corners with three OLiCrCo2 tetrahedra and an edgeedge with one OLiCo2Sn tetrahedra. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, one Cr+4.67+, one Co2+, and one Sn4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one Cr+4.67+, and two Co2+ atoms. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Cr+4.67+, one Co2+, and one Sn4+ atom. In the fifteenth O2- site, O2- is bonded to one Li1+, two Co2+, and one Sn4+ atom to form distorted OLiCo2Sn tetrahedra that share corners with three OLiCrCo2 tetrahedra and an edgeedge with one OLiCrCoSn tetrahedra. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Cr+4.67+, one Co2+, and one Sn4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MnCoCu4(SnS4)2 by Materials Project

MnCoCu4(SnS4)2 is Clathrate-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. Mn2+ is bonded to four S2- atoms to form MnS4 tetrahedra that share corners with four SnS4 tetrahedra and corners with eight CuS4 tetrahedra. There are two shorter (2.38 Å) and two longer (2.39 Å) Mn–S bond lengths. Co2+ is bonded to four S2- atoms to form CoS4 tetrahedra that share corners with four SnS4 tetrahedra and corners with eight CuS4 tetrahedra. There are three shorter (2.27 Å) and one longer (2.28 Å) Co–S bond lengths. There are four inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent MnS4 tetrahedra, corners with two equivalent CoS4 tetrahedra, corners with four CuS4 tetrahedra, and corners with four SnS4 tetrahedra. There are two shorter (2.30 Å) and two longer (2.32 Å) Cu–S bond lengths. In the second Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent MnS4 tetrahedra, corners with two equivalent CoS4 tetrahedra, corners with four CuS4 tetrahedra, and corners with four SnS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.30–2.33 Å. In the third Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share a cornercorner with one CoS4 tetrahedra, corners with three equivalent MnS4 tetrahedra, corners with four CuS4 tetrahedra, and corners with four SnS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.30–2.32 Å. In the fourth Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share a cornercorner with one MnS4 tetrahedra, corners with three equivalent CoS4 tetrahedra, corners with four CuS4 tetrahedra, and corners with four SnS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.31–2.33 Å. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share a cornercorner with one MnS4 tetrahedra, corners with three equivalent CoS4 tetrahedra, and corners with eight CuS4 tetrahedra. There are one shorter (2.48 Å) and three longer (2.49 Å) Sn–S bond lengths. In the second Sn4+ site, Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share a cornercorner with one CoS4 tetrahedra, corners with three equivalent MnS4 tetrahedra, and corners with eight CuS4 tetrahedra. There are three shorter (2.47 Å) and one longer (2.48 Å) Sn–S bond lengths. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded to one Mn2+, two Cu1+, and one Sn4+ atom to form corner-sharing SMnCu2Sn tetrahedra. In the second S2- site, S2- is bonded to one Co2+, two Cu1+, and one Sn4+ atom to form corner-sharing SCoCu2Sn tetrahedra. In the third S2- site, S2- is bonded to one Mn2+, two Cu1+, and one Sn4+ atom to form corner-sharing SMnCu2Sn tetrahedra. In the fourth S2- site, S2- is bonded to one Co2+, two Cu1+, and one Sn4+ atom to form corner-sharing SCoCu2Sn tetrahedra. In the fifth S2- site, S2- is bonded to one Co2+, two Cu1+, and one Sn4+ atom to form corner-sharing SCoCu2Sn tetrahedra. In the sixth S2- site, S2- is bonded to one Mn2+, two Cu1+, and one Sn4+ atom to form corner-sharing SMnCu2Sn tetrahedra. In the seventh S2- site, S2- is bonded to one Mn2+, two Cu1+, and one Sn4+ atom to form corner-sharing SMnCu2Sn tetrahedra. In the eighth S2- site, S2- is bonded to one Co2+, two Cu1+, and one Sn4+ atom to form corner-sharing SCoCu2Sn tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg30CoSnO32 by Materials Project

Mg30CoSnO32 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are eight inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent CoO6 octahedra, corners with two equivalent SnO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.97–2.18 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.09 Å) and four longer (2.15 Å) Mg–O bond lengths. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.12–2.15 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent SnO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.98 Å) and four longer (2.17 Å) Mg–O bond lengths. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CoO6 octahedra, an edgeedge with one SnO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–7°. There are a spread of Mg–O bond distances ranging from 2.11–2.19 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.14–2.16 Å. In the seventh Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CoO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Mg–O bond distances ranging from 2.13–2.16 Å. In the eighth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one SnO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–7°. There are a spread of Mg–O bond distances ranging from 2.11–2.20 Å. Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six MgO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.21 Å) Co–O bond lengths. Sn2+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with six MgO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.32 Å) and two longer (2.33 Å) Sn–O bond lengths. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ and one Co2+ atom to form OMg5Co octahedra that share corners with six OMg5Co octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the second O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg5Co octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the third O2- site, O2- is bonded to five Mg2+ and one Sn2+ atom to form a mixture of edge and corner-sharing OMg5Sn octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 1–3°. In the fifth O2- site, O2- is bonded to five Mg2+ and one Co2+ atom to form a mixture of edge and corner-sharing OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the sixth O2- site, O2- is bonded to five Mg2+ and one Sn2+ atom to form OMg5Sn octahedra that share corners with six OMg5Co octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. The O–Mg bond length is 1.97 Å. In the seventh O2- site, O2- is bonded to five Mg2+ and one Sn2+ atom to form OMg5Sn octahedra that share corners with six OMg5Co octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of O–Mg bond distances ranging from 1.97–2.20 Å. In the eighth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the ninth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg5Sn octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the tenth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg5Sn octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are two shorter (2.11 Å) and two longer (2.15 Å) O–Mg bond lengths. In the eleventh O2- site, O2- is bonded to five Mg2+ and one Sn2+ atom to form OMg5Sn octahedra that share corners with six OMg5Co octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. Both O–Mg bond lengths are 2.20 Å. In the twelfth O2- site, O2- is bonded to five Mg2+ and one Co2+ atom to form a mixture of edge and corner-sharing OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of O–Mg bond distances ranging from 2.11–2.17 Å. In the thirteenth O2- site, O2- is bonded to five Mg2+ and one Sn2+ atom to form OMg5Sn octahedra that share corners with six OMg5Sn octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are two shorter (2.19 Å) and two longer (2.20 Å) O–Mg bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Precisely doping the surface of tin-based electrocatalysts for improved CO 2 conversion to liquid chemicals

Doping tin catalysts with sulfur can improve the electrochemical CO 2 conversion into formate/formic acid, but the lack of composition-dependent activity trends hinders further catalyst development. Here, we precisely controlled the composition of sulfur-doped Sn catalysts to show that sulfur doping only improves CO 2 conversion over a very narrow composition range, achieving maximum activity at 1.4 at% S. In situ Raman spectroscopy indicted working catalysts were in a primarily metallic state (e.g. S-Sn), and we achieved some of the highest reported partial current densities in both H-cell and full-cell electrolyzer configurations. Density Functional Theory calculations predicted S atoms preferentially occupied the catalyst surface and improved CO 2 reduction by localizing charge density at the catalyst/intermediate interface, which stabilized the *OCOH intermediate and lowered the CO 2 conversion thermodynamic barrier. Our work quantifies the composition-dependent influence of S dopants on Sn-based CO 2 reduction catalysts and provides a pathway for maximizing their CO 2 conversion activity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on Mg30CoSnO32 by Materials Project

Mg30CoSnO32 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are eight inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.15 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent SnO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.97–2.19 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Mg–O bond lengths are 2.14 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.17 Å) Mg–O bond lengths. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CoO6 octahedra, an edgeedge with one SnO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Mg–O bond distances ranging from 2.11–2.20 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.14–2.16 Å. In the seventh Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CoO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are two shorter (2.14 Å) and four longer (2.15 Å) Mg–O bond lengths. In the eighth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one SnO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–7°. There are a spread of Mg–O bond distances ranging from 2.11–2.19 Å. Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with two equivalent SnO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.03 Å) and four longer (2.18 Å) Co–O bond lengths. Sn2+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.29 Å) and four longer (2.32 Å) Sn–O bond lengths. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ and one Co2+ atom to form OMg5Co octahedra that share corners with six OMg5Sn octahedra and edges with twelve OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the second O2- site, O2- is bonded to five Mg2+ and one Sn2+ atom to form OMg5Sn octahedra that share corners with six OMg5Co octahedra and edges with twelve OMg5Sn octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the third O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. Both O–Mg bond lengths are 2.16 Å. In the fifth O2- site, O2- is bonded to five Mg2+ and one Co2+ atom to form a mixture of edge and corner-sharing OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of O–Mg bond distances ranging from 2.11–2.15 Å. In the sixth O2- site, O2- is bonded to five Mg2+ and one Sn2+ atom to form a mixture of edge and corner-sharing OMg5Sn octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are two shorter (2.19 Å) and two longer (2.20 Å) O–Mg bond lengths. In the seventh O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with twelve OMg5Sn octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the eighth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the ninth O2- site, O2- is bonded to four equivalent Mg2+, one Co2+, and one Sn2+ atom to form OMg4CoSn octahedra that share corners with six OMg4CoSn octahedra and edges with twelve OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the tenth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg4CoSn octahedra and edges with twelve OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the eleventh O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg4CoSn octahedra and edges with twelve OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are two shorter (2.12 Å) and two longer (2.15 Å) O–Mg bond lengths. In the twelfth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.

36 MATERIALS SCIENCE↗
NASA NTRS1990

Platinized tin oxide catalysts for CO2 lasers: Effects of pretreatment

Platinized tin oxide surfaces used for low-temperature CO oxidation in CO2 lasers have been characterized before and after reduction in CO at 125 and 250 C using ion scattering spectroscopy (ISS) and X ray photoelectron spectroscopy (XPS). XPS indicates that the Pt is present initially as PtO2. Reduction at 125 C converts the PtO2 to Pt(OH)2 while reduction at 250 C converts the PtO2 to metallic Pt. ISS shows that the Pt in the outermost atomic layer of the catalyst is mostly covered by substrate species during the 250 C reduction. Both the ISS and XPS results are consistent with Pt/Sn alloy formation. The surface dehydration and migration of substrate species over surface Pt and Sn appear to explain why a CO pretreatment at 250 C produces inferior CO oxidation activities compared to a 125 C pretreatment.

Gardner, Steven D.↗
NASA NTRS1989

Platinized tin oxide catalysts for CO2 lasers - Effects of pretreatment

Platinized tin oxide surfaces used for low-temperature CO oxidation in CO2 lasers have been characterized before and after reduction in CO at 125 and 250 C using ion scattering spectroscopy (ISS) and X-ray photoelectron spectroscopy (XPS). XPS indicates that the Pt is present initially as Pto2. Reduction at 125 C converts the PtO2 to Pt(OH)2 while reduction at 250 C converts the PtO2 to metallic Pt. ISS shows that the Pt in the outermost atomic layer of the catalyst is mostly covered by substrate species during the 250 C reduction. Both the ISS and XPS results are consistent with Pt/Sn alloy formation. The surface dehydration and migration of substrate species over surface Pt and Sn appear to explain why a CO pretreatment at 250 C produces inferior CO oxidation activities compared to a 125 C pretreatment.

Gardner, Steven D.↗
DOE OSTI2022

High current density electroreduction of CO 2 into formate with tin oxide nanospheres

In this study, we demonstrate three-dimensional (3D) hollow nanosphere electrocatalysts for CO 2 conversion into formate with excellent H-Cell performance and industrially-relevant current density in a 25 cm 2 membrane electrode assembly electrolyzer device. Varying calcination temperature maximized formate production via optimizing the crystallinity and particle size of the constituent SnO 2 nanoparticles. The best performing SnO 2 nanosphere catalysts contained ~ 7.5 nm nanocrystals and produced 71–81% formate Faradaic efficiency (FE) between -0.9 V and -1.3 V vs. the reversible hydrogen electrode (RHE) at a maximum formate partial current density of 73 ± 2 mA cm geo -2 at -1.3 V vs. RHE. The higher performance of nanosphere catalysts over SnO 2 nanoparticles and commercially-available catalyst could be ascribed to their initial structure providing higher electrochemical surface area and preventing extensive nanocrystal growth during CO 2 reduction. Our results are among the highest performance reported for SnO 2 electrocatalysts in aqueous H-cells. We observed an average 68 ± 8% FE over 35 h of operation with multiple on/off cycles. In situ Raman and time-dependent X-ray diffraction measurements identified metallic Sn as electrocatalytic active sites during long-term operation. Further evaluation in a 25 cm 2 electrolyzer cell demonstrated impressive performance with a sustained current density of 500 mA cm geo -2 and an average 75 ± 6% formate FE over 24 h of operation. Our results provide additional design concepts for boosting the performance of formate-producing catalysts.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co2SnC8(ClO4)2 by Materials Project

(Co(CO)4)2SnCl2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four 7772-99-8 molecules and eight Co(CO)4 clusters. In four of the Co(CO)4 clusters, Co2+ is bonded in a trigonal pyramidal geometry to four C+1.25+ atoms. There are a spread of Co–C bond distances ranging from 1.78–1.80 Å. There are four inequivalent C+1.25+ sites. In the first C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In four of the Co(CO)4 clusters, Co2+ is bonded in a trigonal pyramidal geometry to four C+1.25+ atoms. There are a spread of Co–C bond distances ranging from 1.78–1.80 Å. There are four inequivalent C+1.25+ sites. In the first C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li4Co2Ni3Sn(PO4)6 by Materials Project

Li4Co2Ni3Sn(PO4)6 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.07–2.52 Å. In the second Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 1.99–2.62 Å. In the third Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 2.00–2.65 Å. In the fourth Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 1.98–2.67 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form distorted CoO6 octahedra that share corners with six PO4 tetrahedra, a faceface with one NiO6 octahedra, and a faceface with one SnO6 octahedra. There are a spread of Co–O bond distances ranging from 2.02–2.28 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form distorted CoO6 octahedra that share corners with six PO4 tetrahedra and faces with two NiO6 octahedra. There are a spread of Co–O bond distances ranging from 2.05–2.23 Å. There are three inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six O2- atoms to form distorted NiO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one CoO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.99–2.11 Å. In the second Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one CoO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.00–2.10 Å. In the third Ni2+ site, Ni2+ is bonded to six O2- atoms to form distorted NiO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one CoO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.00–2.14 Å. Sn4+ is bonded to six O2- atoms to form distorted SnO6 octahedra that share corners with six PO4 tetrahedra and a faceface with one CoO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.01–2.13 Å. There are six inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SnO6 octahedra, corners with two CoO6 octahedra, and corners with three NiO6 octahedra. The corner-sharing octahedra tilt angles range from 32–52°. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SnO6 octahedra, corners with two CoO6 octahedra, and corners with three NiO6 octahedra. The corner-sharing octahedra tilt angles range from 23–50°. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SnO6 octahedra, corners with two CoO6 octahedra, and corners with three NiO6 octahedra. The corner-sharing octahedra tilt angles range from 22–52°. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SnO6 octahedra, corners with two CoO6 octahedra, and corners with three NiO6 octahedra. The corner-sharing octahedra tilt angles range from 32–51°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the fifth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SnO6 octahedra, corners with two CoO6 octahedra, and corners with three NiO6 octahedra. The corner-sharing octahedra tilt angles range from 32–50°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. In the sixth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SnO6 octahedra, corners with two CoO6 octahedra, and corners with three NiO6 octahedra. The corner-sharing octahedra tilt angles range from 33–52°. There are a spread of P–O bond distances ranging from 1.52–1.56 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ni2+ and one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Ni2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Co2+, one Ni2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Ni2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, one Sn4+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Co2+, one Ni2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Co2+, one Ni2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, one Co2+, one Ni2+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ni2+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one Co2+, one Ni2+, and one P5+ atom. In the eleventh O2- site, O2- is bonded to one Li1+, one Co2+, one Sn4+, and one P5+ atom to form distorted corner-sharing OLiCoSnP trigonal pyramids. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ni2+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, one Sn4+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded to one Li1+, one Co2+, one Ni2+, and one P5+ atom to form distorted corner-sharing OLiCoNiP trigonal pyramids. In the fifteenth O2- site, O2- is bonded in a 5-coordinate geometry to two Li1+, one Co2+, one Ni2+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, one Sn4+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a 5-coordinate geometry to two Li1+, one Co2+, one Ni2+, and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, one Co2+, one Sn4+, and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a 5-coordinate geometry to two Li1+, one Co2+, one Ni2+, and one P5+ atom. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Ni2+, and one P5+ atom. In the twenty-first O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Ni2+, and one P5+ atom. In the twenty-second O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, one Co2+, one Sn4+, and one P5+ atom. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Ni2+, and one P5+ atom. In the twenty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Ni2+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Understanding Inlet Concentration Effects on the Electrocatalytic Conversion of CO 2 to Formic Acid in Gas-Fed Electrolyzers

The electrochemical CO 2 reduction reaction (CO2RR) to produce value-added products remains a developing technology for utilizing waste CO 2 streams. Most device-level CO2RR studies use pure CO 2 gas feeds; however, the effect of dilute CO 2 on the electrolyzer performance is an important consideration for large-scale electrolyzer operation, single-pass conversion, and real-world CO 2 source utilization. This work investigates the effect that the CO 2 concentration has on the performance of formic acid (HCOOH) producing tin oxide (SnO 2 ) and bismuth oxide (Bi 2 O 3 ) catalysts in an electrolyzer device setting. Surprisingly, SnO2 demonstrated an approximately 20% increase in HCOOH selectivity (Faradaic efficiency) when the CO 2 concentration decreased from 100 to 20%. In contrast, Bi 2 O 3 consistently demonstrated high selectivity toward HCOOH across the same CO 2 concentration range. The effects of the CO 2 concentration on selectivity were further investigated with half-cell experiments and in situ Raman spectroscopy, which revealed dynamic changes in the cathodic overpotential and chemical state of the catalyst that depended on the CO 2 concentration. Density functional theory calculations showed how changes in the surface oxidation state of Sn, varying from fully oxidized SnO 2 to metallic Sn(0), affect the thermodynamic barriers of the three main observed products: HCOOH, CO, and H 2 . Our results indicate that dilute CO 2 concentrations required larger cathodic overpotentials to sustain a fixed current density, which, in turn, pushed the Sn-based catalyst toward a more reduced surface that was favorable to HCOOH formation. On the other hand, the Bi-based catalyst remained in a metallic state at CO2RR-relevant potentials and demonstrated a consistent product selectivity regardless of CO 2 concentration. These findings highlight how varying the CO 2 inlet gas concentrations affects the chemical state of catalysts and the resulting performance metrics.

42 ENGINEERING↗