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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Sr(CO2)3 by Materials Project

Sr(CO2)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.57–2.84 Å. There are three inequivalent C+3.33+ sites. In the first C+3.33+ site, C+3.33+ is bonded in a bent 150 degrees geometry to two O2- atoms. There is one shorter (1.22 Å) and one longer (1.23 Å) C–O bond length. In the second C+3.33+ site, C+3.33+ is bonded in a bent 150 degrees geometry to two O2- atoms. There is one shorter (1.21 Å) and one longer (1.23 Å) C–O bond length. In the third C+3.33+ site, C+3.33+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.27 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one C+3.33+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+3.33+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one C+3.33+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one C+3.33+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Sr2+ and one C+3.33+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one C+3.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCo2(AsO4)2 by Materials Project

SrCo2(AsO4)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Sr2+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Sr–O bond distances ranging from 1.76–2.34 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Co–O bond distances ranging from 1.29–2.28 Å. In the second Co2+ site, Co2+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of Co–O bond distances ranging from 1.73–2.44 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded in a 1-coordinate geometry to four O2- atoms. There are a spread of As–O bond distances ranging from 1.17–2.46 Å. In the second As5+ site, As5+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of As–O bond distances ranging from 1.69–2.50 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Co2+ and one As5+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one As5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Co2+ and two As5+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Co2+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a water-like geometry to one Sr2+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to one Co2+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Sr2+ and one As5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and one As5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr4Co(IrO4)3 by Materials Project

Sr4Co(IrO4)3 is Orthorhombic Perovskite-derived structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.48–2.81 Å. In the second Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.46–2.82 Å. There are three inequivalent Ir+4.67+ sites. In the first Ir+4.67+ site, Ir+4.67+ is bonded to six O2- atoms to form corner-sharing IrO6 octahedra. The corner-sharing octahedra tilt angles range from 25–27°. There are two shorter (2.04 Å) and four longer (2.05 Å) Ir–O bond lengths. In the second Ir+4.67+ site, Ir+4.67+ is bonded to six O2- atoms to form IrO6 octahedra that share corners with two equivalent CoO6 octahedra and corners with four equivalent IrO6 octahedra. The corner-sharing octahedra tilt angles range from 18–27°. There are two shorter (1.95 Å) and four longer (2.05 Å) Ir–O bond lengths. In the third Ir+4.67+ site, Ir+4.67+ is bonded to six O2- atoms to form IrO6 octahedra that share corners with two equivalent IrO6 octahedra and corners with four equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 19–25°. There are a spread of Ir–O bond distances ranging from 1.97–2.03 Å. Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six IrO6 octahedra. The corner-sharing octahedra tilt angles range from 18–22°. There are two shorter (2.06 Å) and four longer (2.08 Å) Co–O bond lengths. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three Sr2+, one Ir+4.67+, and one Co2+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Sr2+ and two Ir+4.67+ atoms. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Sr2+ and two Ir+4.67+ atoms. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to three Sr2+, one Ir+4.67+, and one Co2+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+ and two Ir+4.67+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+, one Ir+4.67+, and one Co2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrLaTaCoO6 by Materials Project

SrLaTaCoO6 is (Cubic) Perovskite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are six inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with nine SrO12 cuboctahedra, faces with three equivalent SrO12 cuboctahedra, faces with three equivalent LaO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four CoO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.69–3.12 Å. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with three equivalent SrO12 cuboctahedra, faces with three equivalent LaO12 cuboctahedra, faces with three equivalent CoO6 octahedra, and faces with five TaO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.76–2.90 Å. In the third Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six LaO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four CoO6 octahedra. There are nine shorter (2.84 Å) and three longer (2.86 Å) Sr–O bond lengths. In the fourth Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra, corners with six LaO12 cuboctahedra, faces with six SrO12 cuboctahedra, faces with two CoO6 octahedra, and faces with six TaO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.84–2.91 Å. In the fifth Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six LaO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four CoO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.83–2.86 Å. In the sixth Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with nine SrO12 cuboctahedra, faces with six LaO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four CoO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.83–2.87 Å. There are six inequivalent La3+ sites. In the first La3+ site, La3+ is bonded to twelve O2- atoms to form LaO12 cuboctahedra that share corners with three equivalent SrO12 cuboctahedra, corners with nine LaO12 cuboctahedra, faces with six SrO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four CoO6 octahedra. There are a spread of La–O bond distances ranging from 2.82–2.84 Å. In the second La3+ site, La3+ is bonded to twelve O2- atoms to form LaO12 cuboctahedra that share corners with twelve LaO12 cuboctahedra, faces with six SrO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four CoO6 octahedra. There are six shorter (2.84 Å) and six longer (2.85 Å) La–O bond lengths. In the third La3+ site, La3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are three shorter (2.45 Å) and six longer (2.87 Å) La–O bond lengths. In the fourth La3+ site, La3+ is bonded to twelve O2- atoms to form LaO12 cuboctahedra that share corners with twelve LaO12 cuboctahedra, faces with six SrO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four CoO6 octahedra. There are a spread of La–O bond distances ranging from 2.83–2.86 Å. In the fifth La3+ site, La3+ is bonded to twelve O2- atoms to form LaO12 cuboctahedra that share corners with twelve LaO12 cuboctahedra, faces with three equivalent SrO12 cuboctahedra, faces with four TaO6 octahedra, and faces with four CoO6 octahedra. There are a spread of La–O bond distances ranging from 2.83–2.85 Å. In the sixth La3+ site, La3+ is bonded to twelve O2- atoms to form LaO12 cuboctahedra that share corners with three equivalent SrO12 cuboctahedra, corners with nine LaO12 cuboctahedra, faces with three equivalent SrO12 cuboctahedra, faces with two TaO6 octahedra, and faces with six CoO6 octahedra. There are nine shorter (2.84 Å) and three longer (2.85 Å) La–O bond lengths. There are six inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with three equivalent TaO6 octahedra, corners with three equivalent CoO6 octahedra, a faceface with one LaO12 cuboctahedra, and faces with seven SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. There is three shorter (1.93 Å) and three longer (2.05 Å) Ta–O bond length. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with three equivalent TaO6 octahedra, corners with three equivalent CoO6 octahedra, a faceface with one LaO12 cuboctahedra, and faces with seven SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. There is three shorter (1.94 Å) and three longer (2.05 Å) Ta–O bond length. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six CoO6 octahedra, faces with four SrO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. All Ta–O bond lengths are 1.98 Å. In the fourth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six CoO6 octahedra, faces with four SrO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There is three shorter (1.98 Å) and three longer (1.99 Å) Ta–O bond length. In the fifth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six CoO6 octahedra, faces with four SrO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. All Ta–O bond lengths are 1.98 Å. In the sixth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six CoO6 octahedra, a faceface with one SrO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There is three shorter (1.96 Å) and three longer (2.00 Å) Ta–O bond length. There are six inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with three equivalent TaO6 octahedra, corners with three equivalent CoO6 octahedra, faces with three equivalent LaO12 cuboctahedra, and faces with four SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–5°. There are three shorter (2.02 Å) and three longer (2.06 Å) Co–O bond lengths. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six TaO6 octahedra, faces with three equivalent LaO12 cuboctahedra, and faces with five SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. All Co–O bond lengths are 2.04 Å. In the third Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six TaO6 octahedra, faces with four SrO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are three shorter (2.04 Å) and three longer (2.05 Å) Co–O bond lengths. In the fourth Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six TaO6 octahedra, faces with four SrO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Co–O bond lengths are 2.04 Å. In the fifth Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six TaO6 octahedra, faces with three equivalent SrO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are three shorter (2.04 Å) and three longer (2.05 Å) Co–O bond lengths. In the sixth Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with three equivalent TaO6 octahedra, corners with three equivalent CoO6 octahedra, a faceface with one SrO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are three shorter (1.98 Å) and three longer (2.06 Å) Co–O bond lengths. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to three Sr2+, one La3+, one Ta5+, and one Co2+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to three Sr2+, one La3+, one Ta5+, and one Co2+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two Sr2+, two equivalent La3+, one Ta5+, and one Co2+ atom. In the fifth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Sr2+, two La3+, one Ta5+, and one Co2+ atom. In the sixth O2- site, O2- is bonded in a distorted linear geometry to two Sr2+, two equivalent La3+, one Ta5+, and one Co2+ atom. In the seventh O2- site, O2- is bonded in a distorted linear geometry to two equivalent Sr2+, two La3+, one Ta5+, and one Co2+ atom. In the eighth O2- site, O2- is bonded in a distorted linear geometry to two Sr2+, two equivalent La3+, one Ta5+, and one Co2+ atom. In the ninth O2- site, O2- is bonded in a distorted linear geometry to one Sr2+, two equivalent La3+, one Ta5+, and one Co2+ atom. In the tenth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Sr2+, two La3+, one Ta5+, and one Co2+ atom. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to four La3+, one Ta5+, and one Co2+ atom. In the twelfth O2- site, O2- is bonded to one Sr2+, three La3+, and two Co2+ atoms to form a mixture of distorted corner and face-sharing OSrLa3Co2 octahedra. The corner-sharing octahedra tilt angles range from 3–60°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCo2H2(SeO3)4 by Materials Project

SrCo2H2(SeO3)4 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.55–2.82 Å. In the second Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.58–2.77 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Co–O bond distances ranging from 2.09–2.19 Å. In the second Co2+ site, Co2+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Co–O bond distances ranging from 2.09–2.18 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.60 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are four inequivalent Se4+ sites. In the first Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.73–1.76 Å. In the second Se4+ site, Se4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. All Se–O bond lengths are 1.74 Å. In the third Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.69–1.87 Å. In the fourth Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.69–1.88 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Sr2+, one Co2+, and one Se4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Sr2+, one Co2+, and one Se4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one Co2+, one H1+, and one Se4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Sr2+, one Co2+, and one Se4+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Sr2+, one Co2+, and one Se4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+, one Co2+, and one Se4+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Co2+ and one Se4+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Sr2+, one Co2+, and one Se4+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to one Co2+, one H1+, and one Se4+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Co2+ and one Se4+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one Co2+, and one Se4+ atom. In the twelfth O2- site, O2- is bonded in a distorted single-bond geometry to one Co2+, one H1+, and one Se4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCo3(P2O7)2 by Materials Project

SrCo3(P2O7)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Sr2+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.59–2.76 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six PO4 tetrahedra and edges with two equivalent CoO6 octahedra. There are a spread of Co–O bond distances ranging from 2.10–2.17 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six PO4 tetrahedra and edges with two CoO6 octahedra. There are a spread of Co–O bond distances ranging from 2.10–2.26 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five CoO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–60°. There are a spread of P–O bond distances ranging from 1.53–1.61 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four CoO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–59°. There are a spread of P–O bond distances ranging from 1.52–1.62 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Sr2+, two Co2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Co2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+, one Co2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one Co2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one Co2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Co2+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr3Nb2CoO9 by Materials Project

Sr3Nb2CoO9 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.47–3.08 Å. In the second Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.45–3.11 Å. In the third Sr2+ site, Sr2+ is bonded in a 2-coordinate geometry to seven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.53–3.11 Å. There are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 1.94–2.00 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra and corners with two equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 3–24°. There are a spread of Nb–O bond distances ranging from 1.97–2.04 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.88 Å) and two longer (1.90 Å) Co–O bond length. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with four equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 3–19°. There is two shorter (1.98 Å) and four longer (1.99 Å) Co–O bond length. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+, one Nb5+, and one Co2+ atom. In the second O2- site, O2- is bonded in a water-like geometry to one Nb5+ and one Co2+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to four Sr2+ and one Co2+ atom. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Nb5+, and one Co2+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three Sr2+ and one Nb5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Nb5+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to four Sr2+ and one Nb5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two equivalent Nb5+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+, one Nb5+, and one Co2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCo2(AsO4)2 by Materials Project

SrCo2(AsO4)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Sr2+ is bonded to six O2- atoms to form distorted SrO6 pentagonal pyramids that share corners with four equivalent AsO4 tetrahedra, an edgeedge with one CoO6 octahedra, and an edgeedge with one SrO6 pentagonal pyramid. There are a spread of Sr–O bond distances ranging from 2.42–2.70 Å. There are two 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 AsO4 tetrahedra, an edgeedge with one CoO6 octahedra, and an edgeedge with one SrO6 pentagonal pyramid. There are a spread of Co–O bond distances ranging from 2.08–2.27 Å. In the second Co2+ site, Co2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Co–O bond distances ranging from 1.97–2.32 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.78–1.86 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent CoO6 octahedra and corners with four equivalent SrO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 57–66°. There are a spread of As–O bond distances ranging from 1.72–1.74 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Co2+ and one As5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Co2+ and one O2- atom. The O–O bond length is 1.49 Å. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Co2+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted tetrahedral geometry to one Sr2+, two Co2+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one Co2+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one Co2+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Sr2+, one As5+, and one O2- atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Sr2+ and one As5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrMg30CoO32 by Materials Project

SrMg30CoO32 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Sr2+ is bonded to six O2- atoms to form SrO6 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) Sr–O bond lengths. 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 SrO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent CoO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.97 Å) and four longer (2.18 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 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 SrO6 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 (2.18 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 SrO6 octahedra, an edgeedge with one CoO6 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 1–3°. 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 SrO6 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 2.10–2.20 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 (2.22 Å) Co–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 one Sr2+ and five Mg2+ atoms to form a mixture of edge and corner-sharing OSrMg5 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 0–4°. 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 one Sr2+ and five Mg2+ atoms to form OSrMg5 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 one Sr2+ and five Mg2+ atoms to form OSrMg5 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 octahedra tilt angles range from 0–1°. In the ninth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OSrMg5 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 OSrMg5 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 one Sr2+ and five Mg2+ atoms to form OSrMg5 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 2.11–2.18 Å. In the thirteenth O2- site, O2- is bonded to one Sr2+ and five Mg2+ atoms to form OSrMg5 octahedra that share corners with six OSrMg5 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 OSTI2025

Understanding CO 2 adsorption on the surfaces of SrO and its hydroxylated variants Sr(OH) 2 · n H 2 O ( n = 0, 1, 8)

Strontium oxide (SrO) is a promising material for CO 2 capture through a reversible cycle of carbonation and calcination, where SrO reacts with CO 2 to form SrCO 3 and can be regenerated by calcination. In the presence of moisture, SrO forms strontium hydroxide and its hydrates (Sr(OH) 2 ·nH 2 O). Here, this study, which employs density functional theory, investigates the CO 2 adsorption mechanism of these processes on various crystal surfaces, including SrO, Sr(OH) 2 , Sr(OH) 2 ·1H 2 O, and Sr(OH) 2 ·8H 2 O. A significant finding is that the interaction of CO 2 with these surfaces leads to carbonate/bicarbonate formation via electron transfer, with notable differences in CO 2 orientation and bond characteristics between SrO surfaces and its hydroxylated surfaces. To explore the effects of moisture on CO 2 adsorption, H 2 O adsorption on these stable surfaces was investigated. The results showed that H 2 O reacts with the SrO (100) surface to form hydroxyl (OH) groups while it bonds with the surfaces of Sr(OH) 2 ·nH 2 O (n = 0, 1, 8) with hydrogen bonding. A small amount of H 2 O can enhance CO2 adsorption while a large amount of H 2 O could decrease the capability of CO 2 adsorption.

CO2 capture↗
DOE OSTI2024

A highly oxygen reduction reaction active and CO 2 durable high-entropy cathode for solid oxide fuel cells

One big obstacle for the oxygen reduction reaction (ORR) electrode in solid oxide fuel cells (SOFCs) is the poor reaction activity and fast degradations caused by CO 2 poisoning. Here, in this study, we report our design of an active A-site Ca-rich high-entropy Pr 0.1875 Ba 0.1875 Sr 0.1875 La 0.1875 Ca 0.25 CoO 3-δ (PBSLC 25 C) electrode, guided by the O p-band theory. Here, when applied as a cathode in solid oxide fuel cells (SOFCs), it demonstrates high ORR activity and excellent CO 2 tolerance under realistic operating conditions. Ni-YSZ-based anode-supported cells with PBSLC 25 C cathodes demonstrate excellent peak power densities of 1.14 W cm -2 , 1.04 W cm -2 , and 0.77 W cm -2 in the air with 1%, 5%, and 10% CO 2 , respectively, at 750 °C. The engineered high-entropy PBSLC 25 C effectively diminishes the CO 2 poisoning effect and maintains active surfaces for fast oxygen exchange, as confirmed by the cell durability test in air containing CO 2 (5 and 10 vol%), Raman spectroscopy, and density functional theory calculations.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2023

Unlocking the Potential of A-Site Ca-Doped LaCo 0.2 Fe 0.8 O 3-δ : A Redox-Stable Cathode Material Enabling High Current Density in Direct CO 2 Electrolysis

Massive carbon dioxide (CO 2 ) emission from recent human industrialization has affected the global ecosystem and raised great concern for environmental sustainability. The solid oxide electrolysis cell (SOEC) is a promising energy conversion device capable of efficiently converting CO 2 into valuable chemicals using renewable energy sources. However, Sr-containing cathode materials face the challenge of Sr carbonation during CO 2 electrolysis, which greatly affects the energy conversion efficiency and long-term stability. Thus, A-site Ca-doped La1– x CaxCo 0.2 Fe 0.8 O 3-δ (0.2 ≤ x ≤ 0.6) oxides are developed for direct CO 2 conversion to carbon monoxide (CO) in an intermediate-temperature SOEC (IT-SOEC). With a polarization resistance as low as 0.18 O cm 2 in pure CO 2 atmosphere, a remarkable current density of 2.24 A cm –2 was achieved at 1.5 V with La 0.6 Ca 0.4 Co 0.2 Fe 0.8 O 3-δ (LCCF64) as the cathode in La 0.8 Sr 0.2 Ga 0.83 Mg 0.17 O 3-δ (LSGM) electrolyte (300 µm) supported electrolysis cells using La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) as the air electrode at 800 °C. Furthermore, symmetrical cells with LCCF64 as the electrodes also show promising electrolysis performance of 1.78 A cm –2 at 1.5 V at 800 °C. In addition, stable cell performance has been achieved on direct CO 2 electrolysis at an applied constant current of 0.5 A cm –2 at 800 °C. The easily removable carbonate intermediate produced during direct CO 2 electrolysis makes LCCF64 a promising regenerable cathode. The outstanding electrocatalytic performance of the LCCF64 cathode is ascribed to the highly active and stable metal/perovskite interfaces that resulted from the in situ exsolved Co/CoFe nanoparticles and the additional oxygen vacancies originated from the Ca 2 Fe 2 O 5 phase synergistically providing active sites for CO 2 adsorption and electrolysis. Here this study offers a novel approach to design catalysts with high performance for direct CO 2 electrolysis.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2021

A novel solid oxide electrolytic cell with reduced endothermic load for CO 2 electrolysis using (La 0.80 Sr 0.20 ) 0.95 MnO 3-δ cathode

CO 2 conversion to CO via solid oxide electrolysis provides a potentially efficient method for converting CO 2 into an industrially relevant product. A solid oxide electrolysis cell with (La 0.80 Sr 0.20 ) 0.95 MnO 3-δ (LSM) as the CO 2 reduction cathode, yttrium stabilized zirconia (YSZ) as electrolyte, and nickel as the H 2 oxidation anode was operated 800 °C and 850 °C. Thermogravimetric analysis of the LSM material showed no catalyst oxidation at operating temperatures allowing for CO 2 electrolysis without reducing safe gas. In addition, no cathode material mass gain was observed in the presence of CO suggesting little to no carbon deposition occurred above 750 °C. The formation rates of CO for the cell reached 1.15 mL∙min-1∙ cm -2 for an applied current of 150 mA∙cm -2 achieving a faradaic efficiency of 100 %. Furthermore, the cell displayed good stability in the short-term CO 2 electrolysis test with a nominal voltage drop of 4 mV h -1 for 10 h at 850°C. This study shows the feasibility of operating a solid oxide CO 2 electrolysis cell for CO production with H 2 at the anode to reduce endothermic process load.

(La0.80Sr0.20)0.95MnO3-δ↗
DOE OSTI2026

Perovskite design principles for efficient microwave dry reforming with noble metal free catalysts

Microwave absorbing catalysts have the potential to electrify high-temperature thermal reactions such as the dry reforming of methane process (DRM: CO 2 + CH 4 → 2CO + 2 H 2 ). However, microwave catalysts present unique challenges due to their dual requirements of maintaining microwave absorption in both oxidative and reductive environments and stability across a range of temperatures in inherently non-isothermal reactors. Here, catalyst candidates from the La 0.8 Sr 0.2 CoO 3 -La 0.8 Sr 0.2 NiO 3 -La 0.8 Sr 0.2 MnO 3 perovskite systems were screened (28 total) to identify promising microwave catalysts free of noble metals for dry reforming methane. The best performing candidates met two main criteria. First, they occurred at crystal phase boundaries, giving rise to a pseudocubic perovskite structure. The combined use of Goldschmidt tolerance factor and octahedral tolerance factors appeared to be suitable for predicting pseudocubic perovskites. Second, they provided a balance of reducible metal sites with an irreducible metal oxide support. The best performing catalyst was found to exsolve Ni-Co alloy particles as active sites for the DRM reaction which offered superior resistance to coking for excellent reforming efficiency and stability.

42 ENGINEERING↗
DOE OSTI2022

Rationally designed negative electrode for selective CO 2 -to-CO conversion in protonic ceramic electrochemical cells

Protonic ceramic electrochemical cells (PCECs) are solid-state electrochemical devices that employ proton-conducting oxides as electrolytes, which offer a promising approach for electrification of chemical manufacturing, including CO 2 reduction to produce value-added chemicals (e.g., CO). The primary advantage of PCECs is their intermediate operating temperatures (300–600 °C), which thermodynamically and kinetically favor the CO 2 reduction chemistry at the negative electrode. However, the conventional negative electrodes of PCECs, such as BaZr 0.8–x Ce x Y 0.2 O 3-δ -Ni or BaZr 0.8–x Ce x Y 0.1 Yb 0.1 O 3-δ -Ni, cannot reduce CO 2 to either CH 4 or CO with a selectivity of >99 %, leading to the production of a CO and CH 4 mixture. Herein, an oxide-supported in-situ exsolved Ni-Fe alloyed nanoparticle electrocatalyst, Sr 2 Fe 1.4 Mo 0.5 O 6-δ -Ni0.175 (SFM-Ni0.175), is first employed as the negative electrode of PCECs. The PCECs equipped with this new negative electrode selectively favor the CO 2 -to-CO conversion. A selectivity of ~100 % toward CO has been demonstrated over a wide range of operating temperatures (400–600 °C) and applied potentials/current densities. The negative electrode demonstrated in this work fully suppresses the CH 4 production. In situ diffuse reflectance infrared spectroscopy (DRIFTS) was performed to probe the CO 2 reduction mechanisms over both SFM-Ni0.175 and the traditional negative electrode (BCZYYb7111 +Ni), which indicates SFM-Ni0.175 inhibits the formation of formate species, leading to selective production of CO. Finally, this work validates that PCECs equipped with the rationally designed negative electrode can selectively manufacture chemicals.

25 ENERGY STORAGE↗
DOE OSTI2025

Microwave-Assisted Reactive CO 2 Capture with the SrCO 3 -Graphite System

This study details the initial development of a microwave heat-driven reactive CO 2 capture (RCC) process using the SrO/SrCO 3 cycle and graphitic carbon to absorb ppm-levels of CO 2 from humidified room temperature air and selectively convert it into CO. By combining first-principles density functional theory (DFT) simulations with thermogravimetric analysis (TGA) and X-ray diffraction (XRD) verification, it is demonstrated that SrO spontaneously absorbs moisture to generate Sr(OH) 2 followed by Sr(OH) 2 *1H 2 O, which then can spontaneously react with atmospheric levels of CO 2 to form SrCO 3 . The resulting SrCO 3 can then react with solid carbon at elevated temperatures to selectively produce CO and regenerate SrO. Graphitic carbon is an excellent microwave absorber that can quickly generate temperatures approaching 1000 °C and then cool to room temperature within minutes, potentially allowing for integration with intermittent electricity. It is shown that using microwaves to selectively heat a mixture of graphitic carbon and SrCO 3 produced CO with 85 ± 3% selectivity and stable performance over ten cycles. The rapid heating for release and room temperature CO 2 uptake processes appeared to prevent performance loss from particle sintering typically observed with traditional thermal systems. In conclusion, these results demonstrate a new RCC approach that adds to the growing number of potential technologies available for converting CO 2 to useful chemicals.

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

Advanced sorbents for modular oxygen production for REMS gasifiers

Under a DOE funded effort, Thermosolv LLC has been developing a sorbent-based oxygen production technology for gasification and oxy-combustion applications. The sorbents utilize oxygen-storage properties of certain perovskites to (1) selectively adsorb oxygen at moderate temperature from compressed air and (2) release the adsorbed oxygen into a vacuum or a sweep gas such as CO2 and/or steam. Through cyclic operations of multiple sorbent beds such a process can be made continuous. Pressure drop across the sorbent bed and other similar design considerations dictate that the sorbent be in the form of a high surface-area-to-volume pellet and yet still possess sufficient crush strength and integrity. Process efficiency is determined by the sorption and desorption kinetics and sorbent capacity. Typical process involves cycle times in the order of 100 seconds, a time too short to fully utilize the full volume of the sorbent and the sorption capacity of the sorbent pellets. As a part of this project, Thermosolv LLC undertook the development of oxygen sorbents as a high-surface area supported sorbent on a light-weight inert support to (1) reduce the cost, (2) increase the productivity, and (3) reduce the overall weight of the reactor. Using a previously developed perovskite (LSCF 1991) with its well-characterized performance, composite sorbent pellets each consisting of an inert core coated by a thin layer of the functional perovskite material were produced. Several low-density, inexpensive inert solids supports in the 1/8”-1/4” size were selected to keep the pressure drop across the sorbent bed in the acceptable range. A number of commercial technologies including spray coating, dip coating, incipient impregnation of porous substrate followed by thermal annealing at various temperatures and duration were employed and tested to produce robust composite supported sorbent pellets. A sense of optimum coating thickness was developed by testing sorbent pellets of various increasing diameter pellets. LSCF-1991extrudates ranging in size from 1/32” to 3/16” were tested in a TGA and in a fixed-bed pressure swing test set-up for sorption/desorption cycles of interest. The data show that for the operational conditions of interest the coating thickness for a supported sorbent pellet needs to be approximately 1/32” (about 0.8 mm). Subsequent work thereby concentrated on developing composite pellets of various substrates, shapes and sizes with coating layer of about this size range. Candidate support materials were chosen based on cost, inertness, mechanical strength, thermal expansion and chemical stability with sorbent material, and in a size range to give an acceptable pressure drop in fixed-bad reactor configurations. Coating application methods used for application of the sorbent onto the support included precipitation, spray coating and dip coating from sorbent slurries and sol gels. For all coated supports where we could successfully apply a uniform coating of desired thickness with an acceptable handling performance in terms of exfoliation, TGA-based cyclic sorption/desorption testing was performed to determine cycling capacity of oxygen. Among nearly twenty different support materials tested, best adhesion performance was obtained from stainless saddle supports. In the bench-scale fixed-bad tests stainless steel saddle support composite pellets with a coating thickness in the 0.6 mm or so range, the composite sorbent pellet performance approached up to 95% of that of the 2 mm parent material pellets. In a parallel approach to reducing the cost of the sorbent, alternate sorbent formulations replacing/reducing the amount of cobalt in the LSCF family were also investigated. Successful formulations that could match the performance of LSCF 1991 were identified based on TGA cyclic tests as LSCF 1919 and LSF 1910. In the range of operational envelop of cycle times and other relevant process operating conditions, the reduced Co formulations showed comparable performance in the bench-scale fixed-bad cyclic operations. As a part of this project, we also attempted substitution of La and Sr with Ca and Ba, and Co with Mn, Ni and Cu with little success, but the overall project goal of reducing sorbent cost in terms of raw material and manufacturing expenses was successful.

01 COAL, LIGNITE, AND PEAT↗