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At least 739 records · Page 41
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DOE OSTI2020

Materials Data on CdPd5Se by Materials Project

Pd5CdSe crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a 4-coordinate geometry to two equivalent Pd, two equivalent Cd, and two equivalent Se atoms. Both Pd–Pd bond lengths are 2.88 Å. Both Pd–Cd bond lengths are 2.88 Å. Both Pd–Se bond lengths are 2.55 Å. In the second Pd site, Pd is bonded to eight equivalent Pd and four equivalent Cd atoms to form distorted PdCd4Pd8 cuboctahedra that share corners with four equivalent PdCd4Pd8 cuboctahedra, faces with four equivalent PdCd4Pd8 cuboctahedra, and faces with four equivalent CdPd12 cuboctahedra. All Pd–Cd bond lengths are 2.88 Å. Cd is bonded to twelve Pd atoms to form CdPd12 cuboctahedra that share corners with four equivalent CdPd12 cuboctahedra, faces with four equivalent PdCd4Pd8 cuboctahedra, and faces with four equivalent CdPd12 cuboctahedra. Se is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TlPd5Se by Materials Project

Pd5TlSe crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a 4-coordinate geometry to two equivalent Pd, two equivalent Tl, and two equivalent Se atoms. Both Pd–Pd bond lengths are 2.91 Å. Both Pd–Tl bond lengths are 2.91 Å. Both Pd–Se bond lengths are 2.57 Å. In the second Pd site, Pd is bonded to eight equivalent Pd and four equivalent Tl atoms to form distorted PdTl4Pd8 cuboctahedra that share corners with four equivalent PdTl4Pd8 cuboctahedra, faces with four equivalent PdTl4Pd8 cuboctahedra, and faces with four equivalent TlPd12 cuboctahedra. All Pd–Tl bond lengths are 2.90 Å. Tl is bonded to twelve Pd atoms to form TlPd12 cuboctahedra that share corners with four equivalent TlPd12 cuboctahedra, faces with four equivalent PdTl4Pd8 cuboctahedra, and faces with four equivalent TlPd12 cuboctahedra. Se is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HgPPd5 by Materials Project

Pd5HgP crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a 11-coordinate geometry to seven Pd, two equivalent Hg, and two equivalent P atoms. There are a spread of Pd–Pd bond distances ranging from 2.78–2.94 Å. Both Pd–Hg bond lengths are 2.94 Å. Both Pd–P bond lengths are 2.43 Å. In the second Pd site, Pd is bonded to eight equivalent Pd and four equivalent Hg atoms to form distorted PdHg4Pd8 cuboctahedra that share corners with four equivalent PdHg4Pd8 cuboctahedra, faces with four equivalent PdHg4Pd8 cuboctahedra, and faces with four equivalent HgPd12 cuboctahedra. All Pd–Hg bond lengths are 2.82 Å. Hg is bonded to twelve Pd atoms to form HgPd12 cuboctahedra that share corners with four equivalent HgPd12 cuboctahedra, faces with four equivalent PdHg4Pd8 cuboctahedra, and faces with four equivalent HgPd12 cuboctahedra. P is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZnPd5Se by Materials Project

Pd5ZnSe crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a 4-coordinate geometry to two equivalent Pd, two equivalent Zn, and two equivalent Se atoms. Both Pd–Pd bond lengths are 2.78 Å. Both Pd–Zn bond lengths are 2.78 Å. Both Pd–Se bond lengths are 2.56 Å. In the second Pd site, Pd is bonded to eight equivalent Pd and four equivalent Zn atoms to form PdZn4Pd8 cuboctahedra that share corners with four equivalent PdZn4Pd8 cuboctahedra, faces with four equivalent PdZn4Pd8 cuboctahedra, and faces with four equivalent ZnPd12 cuboctahedra. All Pd–Zn bond lengths are 2.83 Å. Zn is bonded to twelve Pd atoms to form ZnPd12 cuboctahedra that share corners with four equivalent ZnPd12 cuboctahedra, faces with four equivalent PdZn4Pd8 cuboctahedra, and faces with four equivalent ZnPd12 cuboctahedra. Se is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GaPPd5 by Materials Project

Pd5GaP crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a 4-coordinate geometry to seven Pd, two equivalent Ga, and two equivalent P atoms. There are a spread of Pd–Pd bond distances ranging from 2.78–2.86 Å. Both Pd–Ga bond lengths are 2.81 Å. Both Pd–P bond lengths are 2.43 Å. In the second Pd site, Pd is bonded to eight equivalent Pd and four equivalent Ga atoms to form distorted PdGa4Pd8 cuboctahedra that share corners with four equivalent PdGa4Pd8 cuboctahedra, faces with four equivalent PdGa4Pd8 cuboctahedra, and faces with four equivalent GaPd12 cuboctahedra. All Pd–Ga bond lengths are 2.78 Å. Ga is bonded to twelve Pd atoms to form GaPd12 cuboctahedra that share corners with four equivalent GaPd12 cuboctahedra, faces with four equivalent PdGa4Pd8 cuboctahedra, and faces with four equivalent GaPd12 cuboctahedra. P is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MnGe2Pd3 by Materials Project

Pd2(MnPd)Ge2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mn is bonded in a 10-coordinate geometry to six Pd and four equivalent Ge atoms. There are a spread of Mn–Pd bond distances ranging from 2.78–2.85 Å. There are two shorter (2.69 Å) and two longer (2.74 Å) Mn–Ge bond lengths. There are three inequivalent Pd sites. In the first Pd site, Pd is bonded in a 6-coordinate geometry to two equivalent Mn and four Ge atoms. There are a spread of Pd–Ge bond distances ranging from 2.54–2.58 Å. In the second Pd site, Pd is bonded in a 8-coordinate geometry to four equivalent Mn and four Ge atoms. There are a spread of Pd–Ge bond distances ranging from 2.58–2.62 Å. In the third Pd site, Pd is bonded in a 5-coordinate geometry to five Ge atoms. There are a spread of Pd–Ge bond distances ranging from 2.50–2.70 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 8-coordinate geometry to eight Pd atoms. In the second Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent Mn and five Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SiSnPd5 by Materials Project

Pd5SnSi crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pd sites. In the first Pd site, Pd is bonded to eight equivalent Pd and four equivalent Sn atoms to form PdSn4Pd8 cuboctahedra that share corners with four equivalent PdSn4Pd8 cuboctahedra, faces with four equivalent PdSn4Pd8 cuboctahedra, and faces with four equivalent SnPd12 cuboctahedra. All Pd–Pd bond lengths are 2.89 Å. All Pd–Sn bond lengths are 2.84 Å. In the second Pd site, Pd is bonded in a 2-coordinate geometry to two equivalent Pd, two equivalent Sn, and two equivalent Si atoms. Both Pd–Sn bond lengths are 2.89 Å. Both Pd–Si bond lengths are 2.47 Å. Sn is bonded to twelve Pd atoms to form SnPd12 cuboctahedra that share corners with four equivalent SnPd12 cuboctahedra, faces with four equivalent PdSn4Pd8 cuboctahedra, and faces with four equivalent SnPd12 cuboctahedra. Si is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La2Ge4Pd3Pt by Materials Project

La2PtPd3Ge4 crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. La is bonded in a 8-coordinate geometry to two equivalent Pt, six Pd, and eight Ge atoms. Both La–Pt bond lengths are 3.38 Å. All La–Pd bond lengths are 3.38 Å. All La–Ge bond lengths are 3.39 Å. Pt is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Pt–Ge bond lengths are 2.56 Å. There are three inequivalent Pd sites. In the first Pd site, Pd is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Pd–Ge bond lengths are 2.56 Å. In the second Pd site, Pd is bonded in a 12-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Pd–Ge bond lengths are 2.56 Å. In the third Pd site, Pd is bonded in a 4-coordinate geometry to four equivalent La and four equivalent Ge atoms. All Pd–Ge bond lengths are 2.56 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent La, two equivalent Pt, two equivalent Pd, and one Ge atom. The Ge–Ge bond length is 2.56 Å. In the second Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent La, four Pd, and one Ge atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg16Al12Pd by Materials Project

Mg16PdAl12 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are ten inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to four Mg and twelve Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.15–3.30 Å. There are a spread of Mg–Al bond distances ranging from 3.12–3.24 Å. In the second Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.05–3.13 Å. There are a spread of Mg–Al bond distances ranging from 2.94–3.13 Å. In the third Mg site, Mg is bonded in a 1-coordinate geometry to five Mg, one Pd, and six Al atoms. There are two shorter (3.08 Å) and two longer (3.21 Å) Mg–Mg bond lengths. The Mg–Pd bond length is 2.98 Å. There are a spread of Mg–Al bond distances ranging from 2.99–3.33 Å. In the fourth Mg site, Mg is bonded in a 1-coordinate geometry to four Mg, one Pd, and six Al atoms. Both Mg–Mg bond lengths are 3.00 Å. The Mg–Pd bond length is 2.86 Å. There are a spread of Mg–Al bond distances ranging from 3.03–3.14 Å. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to four Mg, one Pd, and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.03–3.28 Å. The Mg–Pd bond length is 3.18 Å. There are a spread of Mg–Al bond distances ranging from 2.85–3.11 Å. In the sixth Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.10–3.16 Å. There are a spread of Mg–Al bond distances ranging from 2.87–3.19 Å. In the seventh Mg site, Mg is bonded in a 2-coordinate geometry to four Mg, one Pd, and five Al atoms. There are one shorter (3.09 Å) and one longer (3.22 Å) Mg–Mg bond lengths. The Mg–Pd bond length is 2.82 Å. There are a spread of Mg–Al bond distances ranging from 2.86–3.16 Å. In the eighth Mg site, Mg is bonded in a 10-coordinate geometry to four Mg and six Al atoms. There are one shorter (3.04 Å) and one longer (3.05 Å) Mg–Mg bond lengths. There are a spread of Mg–Al bond distances ranging from 3.06–3.13 Å. In the ninth Mg site, Mg is bonded in a 1-coordinate geometry to seven Mg, one Pd, and five Al atoms. The Mg–Mg bond length is 3.16 Å. The Mg–Pd bond length is 3.17 Å. There are a spread of Mg–Al bond distances ranging from 2.85–3.23 Å. In the tenth Mg site, Mg is bonded in a 12-coordinate geometry to five Mg and five Al atoms. There are a spread of Mg–Al bond distances ranging from 2.90–3.09 Å. Pd is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. There are one shorter (2.63 Å) and two longer (2.66 Å) Pd–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 1-coordinate geometry to seven Mg, one Pd, and three Al atoms. There are one shorter (2.71 Å) and two longer (2.76 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a distorted q6 geometry to eight Mg and three Al atoms. Both Al–Al bond lengths are 2.75 Å. In the third Al site, Al is bonded in a 10-coordinate geometry to seven Mg and three Al atoms. There are a spread of Al–Al bond distances ranging from 2.69–2.74 Å. In the fourth Al site, Al is bonded in a 10-coordinate geometry to seven Mg and three Al atoms. There are one shorter (2.67 Å) and one longer (2.75 Å) Al–Al bond lengths. In the fifth Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. The Al–Al bond length is 2.73 Å. In the sixth Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. The Al–Al bond length is 2.70 Å. In the seventh Al site, Al is bonded in a 1-coordinate geometry to eight Mg, one Pd, and three Al atoms. The Al–Al bond length is 2.72 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti4H3Pd2 by Materials Project

Ti4Pd2H3 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Ti sites. In the first Ti site, Ti is bonded in a square co-planar geometry to four equivalent Pd and four equivalent H atoms. All Ti–Pd bond lengths are 2.87 Å. All Ti–H bond lengths are 2.03 Å. In the second Ti site, Ti is bonded in a linear geometry to two H atoms. There are one shorter (1.89 Å) and one longer (2.20 Å) Ti–H bond lengths. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a distorted square co-planar geometry to four equivalent H atoms. All Pd–H bond lengths are 2.02 Å. In the second Pd site, Pd is bonded in a 2-coordinate geometry to eight equivalent Ti, four equivalent Pd, and two equivalent H atoms. All Pd–Pd bond lengths are 2.86 Å. Both Pd–H bond lengths are 2.24 Å. There are two inequivalent H sites. In the first H site, H is bonded to two equivalent Ti and four equivalent Pd atoms to form HTi2Pd4 octahedra that share corners with four equivalent HTi2Pd4 octahedra, corners with two equivalent HTi5Pd square pyramids, and edges with four equivalent HTi2Pd4 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second H site, H is bonded to five Ti and one Pd atom to form distorted HTi5Pd square pyramids that share a cornercorner with one HTi2Pd4 octahedra, corners with five equivalent HTi5Pd square pyramids, and edges with four equivalent HTi5Pd square pyramids. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr15Pd5O24 by Materials Project

Sr15Pd5O24 crystallizes in the trigonal R32 space group. The structure is three-dimensional. there are five 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 2.61–2.79 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 2.59–2.85 Å. In the third 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 2.59–2.78 Å. In the fourth Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Sr–O bond lengths are 2.49 Å. In the fifth Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.47 Å) and three longer (2.48 Å) Sr–O bond lengths. There are three inequivalent Pd+3.60+ sites. In the first Pd+3.60+ site, Pd+3.60+ is bonded in an octahedral geometry to six O2- atoms. There are three shorter (2.06 Å) and three longer (2.09 Å) Pd–O bond lengths. In the second Pd+3.60+ site, Pd+3.60+ is bonded in an octahedral geometry to six O2- atoms. There are three shorter (2.08 Å) and three longer (2.10 Å) Pd–O bond lengths. In the third Pd+3.60+ site, Pd+3.60+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Pd–O bond lengths are 2.38 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to five Sr2+ and one Pd+3.60+ atom to form a mixture of distorted edge, face, and corner-sharing OSr5Pd octahedra. The corner-sharing octahedra tilt angles range from 2–66°. In the second O2- site, O2- is bonded to five Sr2+ and one Pd+3.60+ atom to form a mixture of distorted edge, face, and corner-sharing OSr5Pd octahedra. The corner-sharing octahedra tilt angles range from 1–64°. In the third O2- site, O2- is bonded to four Sr2+ and two Pd+3.60+ atoms to form a mixture of distorted edge, face, and corner-sharing OSr4Pd2 octahedra. The corner-sharing octahedra tilt angles range from 2–63°. In the fourth O2- site, O2- is bonded to five Sr2+ and one Pd+3.60+ atom to form a mixture of distorted edge, face, and corner-sharing OSr5Pd octahedra. The corner-sharing octahedra tilt angles range from 1–66°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti2HPd by Materials Project

Ti2PdH crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Ti sites. In the first Ti site, Ti is bonded in a square co-planar geometry to four equivalent Pd and four equivalent H atoms. All Ti–Pd bond lengths are 2.86 Å. All Ti–H bond lengths are 2.05 Å. In the second Ti site, Ti is bonded in a distorted single-bond geometry to four equivalent Pd and one H atom. All Ti–Pd bond lengths are 2.79 Å. The Ti–H bond length is 1.91 Å. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded to eight equivalent Ti atoms to form distorted PdTi8 cuboctahedra that share corners with eight equivalent HTi5Pd square pyramids, edges with four equivalent PdTi8 cuboctahedra, and faces with four equivalent PdTi8 cuboctahedra. In the second Pd site, Pd is bonded in a 2-coordinate geometry to eight equivalent Ti, four equivalent Pd, and two equivalent H atoms. All Pd–Pd bond lengths are 2.90 Å. Both Pd–H bond lengths are 2.15 Å. H is bonded to five Ti and one Pd atom to form distorted HTi5Pd square pyramids that share corners with four equivalent PdTi8 cuboctahedra, corners with five equivalent HTi5Pd square pyramids, and edges with four equivalent HTi5Pd square pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La2Ge4IrPd3 by Materials Project

La2IrPd3Ge4 crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. there are two inequivalent La sites. In the first La site, La is bonded in a 12-coordinate geometry to eight Pd and eight Ge atoms. There are four shorter (3.37 Å) and four longer (3.39 Å) La–Pd bond lengths. There are four shorter (3.31 Å) and four longer (3.40 Å) La–Ge bond lengths. In the second La site, La is bonded in a 12-coordinate geometry to four equivalent Ir, four equivalent Pd, and eight Ge atoms. All La–Ir bond lengths are 3.38 Å. All La–Pd bond lengths are 3.37 Å. There are four shorter (3.30 Å) and four longer (3.37 Å) La–Ge bond lengths. Ir is bonded in a 5-coordinate geometry to four equivalent La and five Ge atoms. There are one shorter (2.44 Å) and four longer (2.53 Å) Ir–Ge bond lengths. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a 9-coordinate geometry to four equivalent La and five Ge atoms. There are one shorter (2.47 Å) and four longer (2.56 Å) Pd–Ge bond lengths. In the second Pd site, Pd is bonded in a 4-coordinate geometry to four La and four Ge atoms. There are two shorter (2.56 Å) and two longer (2.59 Å) Pd–Ge bond lengths. There are three inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent La, one Ir, and four equivalent Pd atoms. In the second Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent La and five Pd atoms. In the third Ge site, Ge is bonded in a 8-coordinate geometry to four La, two equivalent Ir, and two equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on InPd5Se by Materials Project

Pd5InSe crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pd sites. In the first Pd site, Pd is bonded to eight equivalent Pd and four equivalent In atoms to form PdIn4Pd8 cuboctahedra that share corners with four equivalent PdIn4Pd8 cuboctahedra, faces with four equivalent PdIn4Pd8 cuboctahedra, and faces with four equivalent InPd12 cuboctahedra. All Pd–Pd bond lengths are 2.86 Å. All Pd–In bond lengths are 2.90 Å. In the second Pd site, Pd is bonded in a 4-coordinate geometry to two equivalent Pd, two equivalent In, and two equivalent Se atoms. Both Pd–In bond lengths are 2.86 Å. Both Pd–Se bond lengths are 2.57 Å. In is bonded to twelve Pd atoms to form InPd12 cuboctahedra that share corners with four equivalent InPd12 cuboctahedra, faces with four equivalent PdIn4Pd8 cuboctahedra, and faces with four equivalent InPd12 cuboctahedra. Se is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HgPd5Se by Materials Project

Pd5HgSe crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Pd sites. In the first Pd site, Pd is bonded to eight equivalent Pd and four equivalent Hg atoms to form PdHg4Pd8 cuboctahedra that share corners with four equivalent PdHg4Pd8 cuboctahedra, faces with four equivalent PdHg4Pd8 cuboctahedra, and faces with four equivalent HgPd12 cuboctahedra. All Pd–Pd bond lengths are 2.90 Å. All Pd–Hg bond lengths are 2.89 Å. In the second Pd site, Pd is bonded in a 2-coordinate geometry to two equivalent Pd, two equivalent Hg, and two equivalent Se atoms. Both Pd–Hg bond lengths are 2.90 Å. Both Pd–Se bond lengths are 2.55 Å. Hg is bonded to twelve Pd atoms to form HgPd12 cuboctahedra that share corners with four equivalent HgPd12 cuboctahedra, faces with four equivalent PdHg4Pd8 cuboctahedra, and faces with four equivalent HgPd12 cuboctahedra. Se is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Oxophilicity Drives Oxygen Transfer at a Palladium–Silver Interface for Increased CO Oxidation Activity

A single-layer AgO x phase grown on Ag(111) efficiently transfers oxygen to Pd domains at room temperature, rendering the Pd-decorated surface highly reactive toward CO oxidation. Here, oxygen transfer from AgO x to Pd and the surface reactivity toward CO were investigated as a function of the Pd coverage using X-ray photoelectron spectroscopy, surface infrared spectroscopy of adsorbed CO, temperature-programmed reaction spectroscopy, and density functional theory (DFT) calculations. Our results show that all of the oxygen from the AgO x layer (~0.375 monolayer) migrates to the surface of Pd during formation of a nearly complete Pd bilayer at 300 K and that the oxygen coverages generated on Pd increase as the Pd cluster size decreases, reaching values that exceed the oxygen concentration in the AgO x layer by as much as a factor of 2. Experimental measurements and DFT calculations show that preferential binding of oxygen on the edges of the Pd clusters enhances the oxygen coverage on Pd clusters of decreasing size and produces a heterogeneous spatial distribution of oxygen. CO adsorbs in high coverages at 100 K by binding on both the terraces and O-rich edges of the Pd clusters. During subsequent heating, oxidation of the adsorbed CO consumes nearly all of the oxygen that transferred from AgO x to the Pd domains; in contrast, the pure AgO x layer exhibits limited reactivity toward CO adsorbed at 100 K. These results demonstrate that differences in oxophilicity drive facile oxygen transfer from Ag to the edges of Pd nanoclusters and thereby give rise to an efficient pathway for CO oxidation on bimetallic PdAg surfaces. The cooperation between the Pd and Ag domains results in near-interfacial chemistry that may be broadly important in catalysis by bimetallic alloys.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Dynamic Evolution of Palladium Single Atoms on Anatase Titania Support Determines the Reverse Water–Gas Shift Activity

Research interest in single-atom catalysts (SACs) has been continuously rising. However, the lack of understanding of the dynamic behaviors of SACs during applications hinder catalyst development and mechanistic understanding. Herein, we report on the evolution of active sites over Pd/TiO 2 -anatase SAC (Pd 1 /TiO 2 ) in the reverse water-gas shift (rWGS) reaction. Combining kinetics, in-situ characterization, and theory, we show that at T ≥ 350 °C, the reduction of TiO 2 by H 2 alters the coordination environment of Pd, creating Pd sites with partially cleaved Pd-O interfacial bonds and a unique electronic structure that exhibit high intrinsic rWGS activity through the carboxyl pathway. The activation by H 2 is accompanied by the partial sintering of single Pd atoms (Pd 1 ) into disordered, flat, ~1 nm diameter clusters (Pd n ). The highly active Pd sites in the new coordination environment under H 2 are eliminated by oxidation, which, when performed at high temperature, also re-disperses Pd n and facilitates the reduction of TiO 2 . In contrast, Pd 1 sinters into crystalline, ~5 nm particles (Pd NP ) during CO treatment, deactivating Pd 1 /TiO 2 . During the rWGS reaction, the two Pd evolution pathways co-exist. The activation by H 2 dominates, leading to the increasing rate with time-on-stream, and steady-state Pd active sites similar with the ones formed under H 2 . Finally, this work demonstrates how the coordination environment and nuclearity of metal sites on a SAC evolve during catalysis and pre-treatments, and how their activity is modulated by these behaviors. These insights on SAC dynamics and structure-function relationship are valuable to mechanistic understanding and catalyst design.

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

Materials Data on NbPd3 by Materials Project

NbPd3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Nb is bonded to twelve Pd atoms to form NbPd12 cuboctahedra that share corners with four equivalent NbPd12 cuboctahedra, corners with eight equivalent PdNb4Pd8 cuboctahedra, edges with eight equivalent NbPd12 cuboctahedra, edges with sixteen equivalent PdNb4Pd8 cuboctahedra, faces with four equivalent NbPd12 cuboctahedra, and faces with fourteen PdNb4Pd8 cuboctahedra. There are four shorter (2.79 Å) and eight longer (2.83 Å) Nb–Pd bond lengths. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded to four equivalent Nb and eight equivalent Pd atoms to form distorted PdNb4Pd8 cuboctahedra that share corners with four equivalent PdNb4Pd8 cuboctahedra, corners with eight equivalent NbPd12 cuboctahedra, edges with twenty-four PdNb4Pd8 cuboctahedra, faces with six equivalent NbPd12 cuboctahedra, and faces with twelve PdNb4Pd8 cuboctahedra. All Pd–Pd bond lengths are 2.83 Å. In the second Pd site, Pd is bonded to four equivalent Nb and eight Pd atoms to form distorted PdNb4Pd8 cuboctahedra that share corners with twelve equivalent PdNb4Pd8 cuboctahedra, edges with eight equivalent NbPd12 cuboctahedra, edges with sixteen PdNb4Pd8 cuboctahedra, faces with four equivalent NbPd12 cuboctahedra, and faces with fourteen PdNb4Pd8 cuboctahedra. All Pd–Pd bond lengths are 2.79 Å.

36 MATERIALS SCIENCE↗