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At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

How the Arrangement of Platinum Atoms on Ruthenium Nanoparticles Improves Hydrogen Evolution Activity

The platinum‐ruthenium (PtRu) system is highly active for hydrogen evolution reaction (HER) in alkaline media with both Pt and Ru playing active roles in the water dissociation step that generates adsorbed hydrogen atoms. Precise control of the arrangement of Pt atoms on Ru nanoparticles can maximize the Pt‐Ru sites for water dissociation and Pt‐Pt sites for hydrogen production and can considerably improve HER catalytic performance. By directing the growth and distribution of Pt on Ru hourglass nanoparticles, the arrangement of Pt on Ru is controlled into forming Pt islands, small Pt clusters, and strings of a few Pt atoms. Calculations show that the unique atomic string arrangements of Pt on Ru is the thermodynamically favorable configuration. Additionally, these strings have a favorable combination of Pt‐Ru and Pt‐Pt sites, making the Pt‐string on Ru the most active catalyst with a more than fivefold increase in turnover frequency for alkaline HER compared to the Pt‐island on Ru catalyst. The results show how controlling the Pt atomic arrangement on Ru nanoparticle surfaces for the tuning of Pt‐Pt and Pt‐Ru neighboring sites can direct toward a more efficient HER mechanism and thereby significantly enhancing HER performance.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Synergistic ruthenium single-atom and nanoparticles in nickel as cooperative catalysts for the alkaline hydrogen evolution reaction

Efficient hydrogen evolution reaction (HER) catalysts that reduce the use of noble metals and can be synthesized on a large scale are essential for advancing anion exchange membrane water electrolyzers (AEMWEs) toward commercialization. Herein, we present a composite catalyst in which Ru nanoparticles coexist with Ru single-atom alloys (SAAs) dispersed within Ni nanoparticles (Ru-SAA/Ni), creating a highly active HER electrocatalyst. Using a one-pot and scalable synthesis method, we can tune the material composition from SAA, i.e. materials containing atomically dispersed Ru atoms (with ≤0.4 at% Ru) to composite structures in which SAAs coexist with Ru NPs. Comprehensive characterization using XPS, XAS, and TEM confirms Ru-SAA formation at a low Ru content and composite structures at higher contents. Electrochemical evaluations conducted in a three-electrode setup reveal that Ru-SAA/Ni composites achieve HER performance on par with that of Pt/C. Computational insights suggest that water dissociation is significantly faster at the Ru/Ni interface compared with that on extended surfaces. These active sites are thermodynamically as active as basal planes, preventing the excessive accumulation of reaction intermediates (H*, OH*). All these results highlight the synergistic interaction between Ru SAAs and Ru nanoparticles and their potential for large-scale applications with minimal use of precious metals. Finally, the materials are processed and tested in AEMWEs, achieving 1.85 V at 0.5 A cm −2 with a total noble metal loading of only 0.1 mg cm −2 .

Khalil, Gaëlle [Université de Paris (France)]↗
DOE OSTI2020

Materials Data on USnRu by Materials Project

URuSn crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. U is bonded in a 11-coordinate geometry to five Ru and six equivalent Sn atoms. There are four shorter (2.99 Å) and one longer (3.04 Å) U–Ru bond lengths. There are two shorter (3.16 Å) and four longer (3.34 Å) U–Sn bond lengths. There are two inequivalent Ru sites. In the first Ru site, Ru is bonded in a 9-coordinate geometry to three equivalent U and six equivalent Sn atoms. All Ru–Sn bond lengths are 2.74 Å. In the second Ru site, Ru is bonded in a 9-coordinate geometry to six equivalent U and three equivalent Sn atoms. All Ru–Sn bond lengths are 2.78 Å. Sn is bonded in a 12-coordinate geometry to six equivalent U and four Ru atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Al2B2Ru3 by Materials Project

Ru3Al2B2 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Ru sites. In the first Ru site, Ru is bonded in a 10-coordinate geometry to four equivalent Al and six equivalent B atoms. All Ru–Al bond lengths are 2.72 Å. There are four shorter (2.28 Å) and two longer (2.35 Å) Ru–B bond lengths. In the second Ru site, Ru is bonded in a body-centered cubic geometry to eight equivalent Al atoms. All Ru–Al bond lengths are 2.54 Å. Al is bonded in a 9-coordinate geometry to eight Ru and one B atom. The Al–B bond length is 2.55 Å. B is bonded in a 9-coordinate geometry to six equivalent Ru, one Al, and two equivalent B atoms. Both B–B bond lengths are 1.81 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Er3Ru2 by Materials Project

Er3Ru2 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. Er is bonded in a 5-coordinate geometry to five Ru atoms. There are a spread of Er–Ru bond distances ranging from 2.90–3.11 Å. There are two inequivalent Ru sites. In the first Ru site, Ru is bonded in a body-centered cubic geometry to six equivalent Er and two equivalent Ru atoms. Both Ru–Ru bond lengths are 2.36 Å. In the second Ru site, Ru is bonded in a 9-coordinate geometry to nine equivalent Er atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu4Ge6Ru7 by Materials Project

Lu4Ru7Ge6 crystallizes in the cubic Im-3m space group. The structure is three-dimensional. Lu is bonded to six equivalent Ru and six equivalent Ge atoms to form LuGe6Ru6 cuboctahedra that share corners with twelve equivalent LuGe6Ru6 cuboctahedra, faces with six equivalent LuGe6Ru6 cuboctahedra, and faces with two equivalent RuGe6 octahedra. All Lu–Ru bond lengths are 2.94 Å. All Lu–Ge bond lengths are 2.99 Å. There are two inequivalent Ru sites. In the first Ru site, Ru is bonded to six equivalent Ge atoms to form RuGe6 octahedra that share faces with eight equivalent LuGe6Ru6 cuboctahedra. All Ru–Ge bond lengths are 2.61 Å. In the second Ru site, Ru is bonded in a 12-coordinate geometry to four equivalent Lu and four equivalent Ge atoms. All Ru–Ge bond lengths are 2.59 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Lu and five Ru atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on U4As6Ru7 by Materials Project

U4Ru7As6 crystallizes in the cubic Im-3m space group. The structure is three-dimensional. U is bonded to six equivalent Ru and six equivalent As atoms to form UAs6Ru6 cuboctahedra that share corners with twelve equivalent UAs6Ru6 cuboctahedra, corners with twelve equivalent RuU4As4 cuboctahedra, edges with six equivalent RuU4As4 cuboctahedra, faces with six equivalent UAs6Ru6 cuboctahedra, and faces with two equivalent RuAs6 octahedra. All U–Ru bond lengths are 2.95 Å. All U–As bond lengths are 2.99 Å. There are two inequivalent Ru sites. In the first Ru site, Ru is bonded to six equivalent As atoms to form RuAs6 octahedra that share corners with twenty-four equivalent RuU4As4 cuboctahedra and faces with eight equivalent UAs6Ru6 cuboctahedra. All Ru–As bond lengths are 2.58 Å. In the second Ru site, Ru is bonded to four equivalent U and four equivalent As atoms to form distorted RuU4As4 cuboctahedra that share corners with eight equivalent UAs6Ru6 cuboctahedra, corners with twelve equivalent RuU4As4 cuboctahedra, corners with four equivalent RuAs6 octahedra, edges with two equivalent RuU4As4 cuboctahedra, edges with four equivalent UAs6Ru6 cuboctahedra, and faces with four equivalent RuU4As4 cuboctahedra. The corner-sharing octahedral tilt angles are 53°. All Ru–As bond lengths are 2.63 Å. As is bonded in a 9-coordinate geometry to four equivalent U and five Ru atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba7Ru4Cl2O15 by Materials Project

Ba7Ru4O15Cl2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with nine equivalent BaO12 cuboctahedra, faces with three equivalent BaO12 cuboctahedra, and faces with seven RuO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.92–2.99 Å. In the second Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to nine O2- and one Cl1- atom. There are three shorter (2.72 Å) and six longer (2.97 Å) Ba–O bond lengths. The Ba–Cl bond length is 3.16 Å. In the third Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to three equivalent O2- and four equivalent Cl1- atoms. All Ba–O bond lengths are 2.57 Å. There are one shorter (3.22 Å) and three longer (3.51 Å) Ba–Cl bond lengths. In the fourth Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with six equivalent BaO12 cuboctahedra, corners with six equivalent RuO6 octahedra, faces with six equivalent BaO12 cuboctahedra, and faces with six equivalent RuO6 octahedra. The corner-sharing octahedral tilt angles are 10°. There are six shorter (2.94 Å) and six longer (3.01 Å) Ba–O bond lengths. There are two inequivalent Ru+4.50+ sites. In the first Ru+4.50+ site, Ru+4.50+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, faces with three equivalent BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. There are three shorter (1.91 Å) and three longer (2.11 Å) Ru–O bond lengths. In the second Ru+4.50+ site, Ru+4.50+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent RuO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ru–O bond lengths are 2.02 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two Ru+4.50+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to four Ba2+ and one Ru+4.50+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to four Ba2+ and two equivalent Ru+4.50+ atoms. Cl1- is bonded to five Ba2+ atoms to form a mixture of distorted edge and corner-sharing ClBa5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd5(RuO7)2 by Materials Project

Gd5(RuO7)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Gd sites. In the first Gd site, Gd is bonded to seven O atoms to form distorted GdO7 pentagonal bipyramids that share corners with two RuO6 octahedra, corners with three equivalent GdO7 pentagonal bipyramids, edges with two RuO6 octahedra, and edges with two equivalent GdO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 30–37°. There are a spread of Gd–O bond distances ranging from 2.21–2.51 Å. In the second Gd site, Gd is bonded in a distorted square co-planar geometry to eight O atoms. There are four shorter (2.25 Å) and four longer (2.82 Å) Gd–O bond lengths. There are two inequivalent Ru sites. In the first Ru site, Ru is bonded to six O atoms to form RuO6 octahedra that share corners with two equivalent RuO6 octahedra, corners with four equivalent GdO7 pentagonal bipyramids, and edges with four equivalent GdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There is four shorter (1.91 Å) and two longer (2.02 Å) Ru–O bond length. In the second Ru site, Ru is bonded to six O atoms to form RuO6 octahedra that share corners with two equivalent RuO6 octahedra, corners with four equivalent GdO7 pentagonal bipyramids, and edges with four equivalent GdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There is four shorter (1.90 Å) and two longer (2.00 Å) Ru–O bond length. There are four inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to three Gd atoms. In the second O site, O is bonded in a 4-coordinate geometry to three Gd and one Ru atom. In the third O site, O is bonded in a 3-coordinate geometry to two equivalent Gd and one Ru atom. In the fourth O site, O is bonded to two equivalent Gd and two Ru atoms to form distorted corner-sharing OGd2Ru2 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ru3W3C2 by Materials Project

W3Ru3C2 is H-Phase-like structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are two inequivalent W sites. In the first W site, W is bonded to nine W and three equivalent Ru atoms to form WRu3W9 cuboctahedra that share corners with nine equivalent WRu3W9 cuboctahedra, corners with six equivalent CRu6 octahedra, edges with fifteen WRu3W9 cuboctahedra, faces with twelve WRu3W9 cuboctahedra, and a faceface with one CRu6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are six shorter (2.86 Å) and three longer (2.90 Å) W–W bond lengths. All W–Ru bond lengths are 2.76 Å. In the second W site, W is bonded to twelve W atoms to form WW12 cuboctahedra that share corners with six equivalent WW12 cuboctahedra, edges with eighteen WRu3W9 cuboctahedra, and faces with eighteen WRu3W9 cuboctahedra. All W–W bond lengths are 2.86 Å. There are two inequivalent Ru sites. In the first Ru site, Ru is bonded in a 3-coordinate geometry to three equivalent W and three equivalent C atoms. All Ru–C bond lengths are 2.06 Å. In the second Ru site, Ru is bonded to six equivalent C atoms to form edge-sharing RuC6 octahedra. All Ru–C bond lengths are 2.20 Å. C is bonded to six Ru atoms to form CRu6 octahedra that share corners with six equivalent WRu3W9 cuboctahedra, corners with three equivalent CRu6 octahedra, edges with nine equivalent CRu6 octahedra, and a faceface with one WRu3W9 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Al3Ru by Materials Project

Al3Ru is Uranium Silicide-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ru sites. In the first Ru site, Ru is bonded to twelve Al atoms to form RuAl12 cuboctahedra that share corners with six equivalent RuAl12 cuboctahedra, corners with twelve equivalent AlAl8Ru4 cuboctahedra, edges with eighteen AlAl8Ru4 cuboctahedra, faces with eight RuAl12 cuboctahedra, and faces with twelve AlAl8Ru4 cuboctahedra. There are six shorter (2.72 Å) and six longer (2.73 Å) Ru–Al bond lengths. In the second Ru site, Ru is bonded to twelve Al atoms to form RuAl12 cuboctahedra that share corners with twelve equivalent RuAl12 cuboctahedra, edges with twenty-four AlAl8Ru4 cuboctahedra, faces with six equivalent RuAl12 cuboctahedra, and faces with twelve AlAl8Ru4 cuboctahedra. There are six shorter (2.73 Å) and six longer (2.74 Å) Ru–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded to four Ru and eight Al atoms to form distorted AlAl8Ru4 cuboctahedra that share corners with four equivalent RuAl12 cuboctahedra, corners with fourteen equivalent AlAl8Ru4 cuboctahedra, edges with six RuAl12 cuboctahedra, edges with twelve AlAl8Ru4 cuboctahedra, faces with four RuAl12 cuboctahedra, and faces with sixteen AlAl8Ru4 cuboctahedra. There are four shorter (2.73 Å) and four longer (2.74 Å) Al–Al bond lengths. In the second Al site, Al is bonded to four Ru and eight Al atoms to form distorted AlAl8Ru4 cuboctahedra that share corners with twelve equivalent AlAl8Ru4 cuboctahedra, edges with eight RuAl12 cuboctahedra, edges with sixteen AlAl8Ru4 cuboctahedra, faces with four RuAl12 cuboctahedra, and faces with fourteen AlAl8Ru4 cuboctahedra. There are two shorter (2.68 Å) and two longer (2.78 Å) Al–Al bond lengths. In the third Al site, Al is bonded to four Ru and eight Al atoms to form distorted AlAl8Ru4 cuboctahedra that share corners with twelve AlAl8Ru4 cuboctahedra, edges with eight RuAl12 cuboctahedra, edges with sixteen AlAl8Ru4 cuboctahedra, faces with four RuAl12 cuboctahedra, and faces with fourteen AlAl8Ru4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba3FeRu2O9 by Materials Project

Ba3FeRu2O9 is (Cubic) Perovskite-derived structured and crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent FeO6 octahedra, faces with seven BaO12 cuboctahedra, a faceface with one FeO6 octahedra, and faces with six RuO6 octahedra. The corner-sharing octahedral tilt angles are 7°. There are a spread of Ba–O bond distances ranging from 2.84–2.99 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent RuO6 octahedra, faces with seven BaO12 cuboctahedra, faces with three equivalent FeO6 octahedra, and faces with four RuO6 octahedra. The corner-sharing octahedral tilt angles are 11°. There are nine shorter (2.91 Å) and three longer (2.99 Å) Ba–O bond lengths. In the third Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, faces with three equivalent FeO6 octahedra, and faces with five RuO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.89–2.96 Å. There are two inequivalent Ru+4.50+ sites. In the first Ru+4.50+ site, Ru+4.50+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent RuO6 octahedra, corners with three equivalent FeO6 octahedra, and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–5°. There are three shorter (1.99 Å) and three longer (2.01 Å) Ru–O bond lengths. In the second Ru+4.50+ site, Ru+4.50+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent RuO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one FeO6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are three shorter (1.99 Å) and three longer (2.01 Å) Ru–O bond lengths. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent RuO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are three shorter (1.99 Å) and three longer (2.11 Å) Fe–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ba2+, one Ru+4.50+, and one Fe3+ atom to form a mixture of distorted corner and face-sharing OBa4FeRu octahedra. The corner-sharing octahedra tilt angles range from 7–60°. In the second O2- site, O2- is bonded in a distorted linear geometry to four Ba2+ and two Ru+4.50+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one Ru+4.50+, and one Fe3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaCuRu5O11 by Materials Project

BaRu5CuO11 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with six equivalent BaO12 cuboctahedra, edges with six equivalent RuO6 octahedra, edges with three equivalent CuO5 trigonal bipyramids, and faces with six equivalent RuO6 octahedra. There are six shorter (2.92 Å) and six longer (2.98 Å) Ba–O bond lengths. There are two inequivalent Ru+3.80+ sites. In the first Ru+3.80+ site, Ru+3.80+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with six equivalent RuO6 octahedra, corners with three equivalent CuO5 trigonal bipyramids, faces with three equivalent BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are three shorter (2.02 Å) and three longer (2.04 Å) Ru–O bond lengths. In the second Ru+3.80+ site, Ru+3.80+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with four equivalent RuO6 octahedra, corners with two equivalent CuO5 trigonal bipyramids, edges with two equivalent BaO12 cuboctahedra, and edges with four equivalent RuO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are four shorter (2.04 Å) and two longer (2.07 Å) Ru–O bond lengths. Cu1+ is bonded to five O2- atoms to form CuO5 trigonal bipyramids that share corners with twelve RuO6 octahedra and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 42–56°. There are three shorter (1.91 Å) and two longer (2.35 Å) Cu–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ba2+, two equivalent Ru+3.80+, and one Cu1+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ru+3.80+ and one Cu1+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Ru+3.80+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on USbRu by Materials Project

URuSb crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. U is bonded in a 11-coordinate geometry to five Ru and six equivalent Sb atoms. There are four shorter (2.99 Å) and one longer (3.06 Å) U–Ru bond lengths. There are two shorter (3.15 Å) and four longer (3.34 Å) U–Sb bond lengths. There are two inequivalent Ru sites. In the first Ru site, Ru is bonded in a 9-coordinate geometry to three equivalent U and six equivalent Sb atoms. All Ru–Sb bond lengths are 2.76 Å. In the second Ru site, Ru is bonded in a 9-coordinate geometry to six equivalent U and three equivalent Sb atoms. All Ru–Sb bond lengths are 2.79 Å. Sb is bonded in a 10-coordinate geometry to six equivalent U and four Ru atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc4Ge6Ru7 by Materials Project

Sc4Ru7Ge6 crystallizes in the cubic Im-3m space group. The structure is three-dimensional. Sc is bonded to six equivalent Ru and six equivalent Ge atoms to form ScGe6Ru6 cuboctahedra that share corners with twelve equivalent ScGe6Ru6 cuboctahedra, faces with six equivalent ScGe6Ru6 cuboctahedra, and faces with two equivalent RuGe6 octahedra. All Sc–Ru bond lengths are 2.89 Å. All Sc–Ge bond lengths are 2.93 Å. There are two inequivalent Ru sites. In the first Ru site, Ru is bonded to six equivalent Ge atoms to form RuGe6 octahedra that share faces with eight equivalent ScGe6Ru6 cuboctahedra. All Ru–Ge bond lengths are 2.52 Å. In the second Ru site, Ru is bonded in a 12-coordinate geometry to four equivalent Sc and four equivalent Ge atoms. All Ru–Ge bond lengths are 2.57 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Sc and five Ru atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaLiRu5O11 by Materials Project

LiBaRu5O11 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Li1+ is bonded to five O2- atoms to form LiO5 trigonal bipyramids that share corners with twelve RuO6 octahedra and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 40–56°. There are three shorter (1.88 Å) and two longer (2.35 Å) Li–O bond lengths. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with six equivalent BaO12 cuboctahedra, edges with six equivalent RuO6 octahedra, edges with three equivalent LiO5 trigonal bipyramids, and faces with six equivalent RuO6 octahedra. There are six shorter (2.92 Å) and six longer (2.95 Å) Ba–O bond lengths. There are two inequivalent Ru+3.80+ sites. In the first Ru+3.80+ site, Ru+3.80+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with four equivalent RuO6 octahedra, corners with two equivalent LiO5 trigonal bipyramids, edges with two equivalent BaO12 cuboctahedra, and edges with four equivalent RuO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are four shorter (2.03 Å) and two longer (2.06 Å) Ru–O bond lengths. In the second Ru+3.80+ site, Ru+3.80+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with six equivalent RuO6 octahedra, corners with three equivalent LiO5 trigonal bipyramids, faces with three equivalent BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are three shorter (2.00 Å) and three longer (2.03 Å) Ru–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three equivalent Ru+3.80+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to one Li1+, two equivalent Ba2+, and two equivalent Ru+3.80+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Ru+3.80+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Plastic-waste hydrogenolysis over two-dimensional MXene-supported ruthenium catalysts with tunable interlayer spacing

The hydrogenolysis of plastics is limited by active-site inaccessibility and inefficient mass transport of bulky polymer chains. To overcome these challenges, this work developed two-dimensional MXene-supported Ru (Ru@MXene) catalysts. Lyophilization of a solution containing dispersed MXene sheets and Ru precursors enabled the confinement of Ru species within the MXene interlayers, which act as pillars to expand the interlayer spacing. Building on this, a silica-pillared MXene-supported Ru (Ru@P-MXene) with even larger interlayer spacing exhibited a reaction rate of 914.9 g C5–C35 g Ru –1 h –1 for the hydrogenolysis of low-density polyethylene (LDPE) into valuable liquid chemicals (e.g., C 5 –C 35 ). A comparison of product yields between Ru@P-MXene and Ru@MXene suggests that elongated Ru particles confined within the MXene support expose their side facets for the reaction. In conclusion, this work demonstrates a new application of MXene in thermochemical catalysis, offering a solution to the challenges of active-site accessibility, mass transport, and reaction confinement in chemical plastic upcycling.

2D materials↗
DOE OSTI2022

Proton-Coupled Electron Transfer in a Ruthenium(II) Bipyrimidine Complex in Its Ground and Excited Electronic States

In this work, proton-coupled electron transfer (PCET) was studied for the ground and excited electronic states of a [Ru(terpy)(bpm)(OH 2 )(PF 6 ) 2 ] complex, Ru-bpm. Cyclic voltammetry measurements show that the Ru(II)-aqua moiety undergoes PCET to form a Ru(IV)-oxo moiety in the anodic region, while the bpm ligand undergoes PCET to form bpmH 2 in the cathodic region. The photophysical behavior of Ru-bpm was studied using steady-state and femtosecond transient UV–vis absorption spectroscopy, coupled with density functional theory (DFT) calculations. The lowest-lying excited state of Ru-bpm is described as a (Ru → bpm) metal-to-ligand charge-transfer (MLCT) state, while the metal-centered (MC) excited state was found computationally to be close in energy to the lowest-energy bright MLCT state (MC state was 0.16 eV above the MLCT state). The excited-state kinetics of Ru-bpm were found via transient absorption spectroscopy to be short-lived and were fit well to a biexponential function with lifetimes $τ_1$ = 4 ps and $τ_2$ = 65 ps in aqueous solution. Kinetic isotope effects of 1.75 ($τ_1$) and 1.61 ($τ_2$) were observed for both decay components, indicating that the solvent plays an important role in the excited-state dynamics of Ru-bpm. Based on the pH-dependent studies and the results from prior studies of similar Ru-complexes, we hypothesize that the 3 MLCT state forms an excited-state hydrogen-bond adduct with the solvent molecules and that this process occurs with a 4 ps lifetime. The formation of such a hydrogen-bond complex is consistent with the electronic density accumulation at the peripheral N atoms of the bpm moiety in the 3 MLCT state. The hydrogen-bonded state 3 MLCT decays to the ground state with a 65 ps lifetime. Such a short lifetime is likely associated with the efficient vibrational energy transfer from the 3 MLCT state to the solvent.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗