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At least 1,279 records · Page 71
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DOE OSTI2021

The Influence of Transitional Metal Dopants on Reducing Chlorine Evolution during the Electrolysis of Raw Seawater

Electrocatalytic water splitting is a possible route to the expanded generation of green hydrogen; however, a long-term challenge is the requirement of fresh water as an electrolyzer feed. The use of seawater as a direct feed for electrolytic hydrogen production would alleviate fresh water needs and potentially open an avenue for locally generated hydrogen from marine hydrokinetic or off-shore power sources. One environmental limitation to seawater electrolysis is the generation of chlorine as a competitive anodic reaction. This work evaluates transition metal (W, Co, Fe, Sn, and Ru) doping of Mn-Mo-based catalysts as a strategy to suppress chlorine evolution while sustaining catalytic efficiency. Electrochemical evaluations in neutral chloride solution and raw seawater showed the promise of a novel Mn-Mo-Ru electrode system for oxygen evolution efficiency and enhanced catalytic activity. Subsequent stability testing in a flowing raw seawater flume highlighted the need for improved catalyst stability for long-term applications of Mn-Mo-Ru catalysts. This work highlights that elements known to be selective toward chlorine evolution in simple oxide form (e.g., RuO2) may display different trends in selectivity when used as isolated dopants, where Ru suppressed chlorine evolution in Mn-based catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

A dual promotional effect of doping tantalum (Ta) in atomically dispersed Ru/CeO 2 catalyst toward CO 2 methanation: Enhanced associative adsorption of CO 2 and activation of H 2

Precisely controlling the product selectivity in CO 2 hydrogenation through rational catalyst design presents a promising approach to mitigate environmental and energy-related challenges, though it remains a significant scientific hurdle. Herein, the CH 4 selectivity of 0.5 wt% Ru loaded catalysts at 250 °C was effectively shifted from approximately 35 % to 100 % through the incorporation of Ta dopant into the CeO 2 support. The EXAFS spectra in conjunction with CO DRIFTS experiment indicated the presence of atomically dispersed Ru particles anchored on the Ta-doped CeO 2 surface. A higher oxidized CeO 2 surface was evidenced in the presence of Ta dopant. The presence of Ta dopant also improved the dispersion of Ru species and their interaction with the support. Most importantly, the Ru/Ta-CeO 2 catalyst exhibited a pronounced capacity for associative CO 2 -adsorption under atmospheric pressure at 50 °C. An improved H 2 activation was also observed under CO 2 hydrogenation conditions. This novel finding of the dual promotional effect of Ta carries a significant impact in the field of CO 2 capture and utilization.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

Base-Free Catalytic Transfer Hydrogenation of Alkyl Formates and Organic Esters at Mild Temperature

The pincer-ligated ruthenium complex ( iPr PN H P)Ru(CO)H 2 ( iPr PN H P = ( i Pr 2 PC 2 H 4 ) 2 NH) is an active catalyst for the transfer hydrogenation of alkyl formates (HCO 2 R) and organic esters (RCO 2 R′) to the corresponding alcohols under base-free reaction conditions at mild temperatures. Specifically, a range of alkyl formate esters were reduced to MeOH and the corresponding alcohols in high yields using ( iPr PN H P)Ru(CO)H 2 as the catalyst and isopropanol ( i PrOH) as the hydrogen donor at 30 °C. The first step in the process is the metal-catalyzed transesterification of the alkyl formate with i PrOH to generate isopropyl formate, which is then reduced. The use of i PrOH as the hydrogen donor is crucial. ( iPr PN H P)Ru(CO)H 2 can also catalyze the transfer hydrogenation of a broad range of organic esters, including cyclic, acyclic, heteroatom-substituted, and long-chain bio-derived esters, to the corresponding alcohols in good yields using ethanol (EtOH) as the hydrogen donor at 55 °C. Computational studies were used to elucidate the proposed pathway for alkyl formate reduction and the underlying reasons why i PrOH is the most effective hydrogen donor for alkyl formate reduction, while EtOH is optimal for organic ester reduction. Overall, this work describes a highly active catalyst for alkyl formate and organic ester transfer hydrogenation and provides mechanistic insight into the factors responsible for the strong catalytic performance. Finally, these findings will be valuable for designing catalysts for both transfer hydrogenation and related reactions.

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

Materials Data on Ce(P3Ru)4 by Materials Project

CeRu4P12 crystallizes in the cubic Im-3 space group. The structure is three-dimensional. Ce3+ is bonded to twelve equivalent P1- atoms to form CeP12 cuboctahedra that share faces with eight equivalent RuP6 octahedra. All Ce–P bond lengths are 3.11 Å. Ru+2.25+ is bonded to six equivalent P1- atoms to form RuP6 octahedra that share corners with six equivalent RuP6 octahedra and faces with two equivalent CeP12 cuboctahedra. The corner-sharing octahedral tilt angles are 62°. All Ru–P bond lengths are 2.36 Å. P1- is bonded in a 5-coordinate geometry to one Ce3+, two equivalent Ru+2.25+, and two equivalent P1- atoms. There are one shorter (2.32 Å) and one longer (2.33 Å) P–P bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(BRu)4 by Materials Project

Y(RuB)4 crystallizes in the tetragonal I4_1/acd space group. The structure is three-dimensional. Y3+ is bonded in a 12-coordinate geometry to twelve equivalent B3- atoms. There are a spread of Y–B bond distances ranging from 2.97–3.22 Å. Ru+2.25+ is bonded to five equivalent B3- atoms to form a mixture of distorted edge and corner-sharing RuB5 trigonal bipyramids. There are a spread of Ru–B bond distances ranging from 2.15–2.29 Å. B3- is bonded in a 6-coordinate geometry to three equivalent Y3+, five equivalent Ru+2.25+, and one B3- atom. The B–B bond length is 1.80 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu(SiRu)2 by Materials Project

LuRu2Si2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Lu3+ is bonded in a 8-coordinate geometry to eight equivalent Si4- atoms. All Lu–Si bond lengths are 3.19 Å. Ru+2.50+ is bonded to four equivalent Si4- atoms to form a mixture of edge and corner-sharing RuSi4 tetrahedra. All Ru–Si bond lengths are 2.37 Å. Si4- is bonded in a 4-coordinate geometry to four equivalent Lu3+ and four equivalent Ru+2.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Al2Ru by Materials Project

RuAl2 is Titanium Disilicide structured and crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Ru is bonded in a distorted q6 geometry to ten equivalent Al atoms. There are a spread of Ru–Al bond distances ranging from 2.59–2.74 Å. Al is bonded in a 10-coordinate geometry to five equivalent Ru and five equivalent Al atoms. There are a spread of Al–Al bond distances ranging from 2.61–2.75 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LuRu by Materials Project

LuRu is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Lu is bonded in a body-centered cubic geometry to eight equivalent Ru atoms. All Lu–Ru bond lengths are 2.89 Å. Ru is bonded in a body-centered cubic geometry to eight equivalent Lu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NbRu by Materials Project

NbRu is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Nb is bonded in a body-centered cubic geometry to eight equivalent Ru atoms. All Nb–Ru bond lengths are 2.76 Å. Ru is bonded in a body-centered cubic geometry to eight equivalent Nb atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuRu by Materials Project

PuRu is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pu is bonded in a body-centered cubic geometry to eight equivalent Ru atoms. All Pu–Ru bond lengths are 2.83 Å. Ru is bonded in a body-centered cubic geometry to eight equivalent Pu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaRu by Materials Project

RuTa is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Ta is bonded in a body-centered cubic geometry to eight equivalent Ru atoms. All Ta–Ru bond lengths are 2.75 Å. Ru is bonded in a body-centered cubic geometry to eight equivalent Ta atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr3Ru by Materials Project

Cr3Ru crystallizes in the cubic Pm-3n space group. The structure is three-dimensional. Cr is bonded in a 6-coordinate geometry to two equivalent Cr and four equivalent Ru atoms. Both Cr–Cr bond lengths are 2.32 Å. All Cr–Ru bond lengths are 2.59 Å. Ru is bonded to twelve equivalent Cr atoms to form a mixture of face and edge-sharing RuCr12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Si2Ru by Materials Project

RuSi2 is Fluorite structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ru is bonded in a body-centered cubic geometry to eight equivalent Si atoms. All Ru–Si bond lengths are 2.46 Å. Si is bonded to four equivalent Ru atoms to form a mixture of corner and edge-sharing SiRu4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tb(P3Ru)4 by Materials Project

TbRu4P12 crystallizes in the cubic Im-3 space group. The structure is three-dimensional. Tb3+ is bonded to twelve equivalent P1- atoms to form TbP12 cuboctahedra that share faces with eight equivalent RuP6 octahedra. All Tb–P bond lengths are 3.11 Å. Ru+2.25+ is bonded to six equivalent P1- atoms to form RuP6 octahedra that share corners with six equivalent RuP6 octahedra and faces with two equivalent TbP12 cuboctahedra. The corner-sharing octahedral tilt angles are 62°. All Ru–P bond lengths are 2.36 Å. P1- is bonded in a 5-coordinate geometry to one Tb3+, two equivalent Ru+2.25+, and two equivalent P1- atoms. Both P–P bond lengths are 2.31 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on VRu by Materials Project

RuV is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. V is bonded in a body-centered cubic geometry to eight equivalent Ru atoms. All V–Ru bond lengths are 2.61 Å. Ru is bonded in a body-centered cubic geometry to eight equivalent V atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KRuO4 by Materials Project

KRuO4 crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. K is bonded in a 8-coordinate geometry to eight equivalent O atoms. There are four shorter (2.85 Å) and four longer (2.91 Å) K–O bond lengths. Ru is bonded in a tetrahedral geometry to four equivalent O atoms. All Ru–O bond lengths are 1.75 Å. O is bonded in a distorted single-bond geometry to two equivalent K and one Ru atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La(P3Ru)4 by Materials Project

LaRu4P12 crystallizes in the cubic Im-3 space group. The structure is three-dimensional. La3+ is bonded to twelve equivalent P1- atoms to form LaP12 cuboctahedra that share faces with eight equivalent RuP6 octahedra. All La–P bond lengths are 3.13 Å. Ru+2.25+ is bonded to six equivalent P1- atoms to form RuP6 octahedra that share corners with six equivalent RuP6 octahedra and faces with two equivalent LaP12 cuboctahedra. The corner-sharing octahedral tilt angles are 62°. All Ru–P bond lengths are 2.37 Å. P1- is bonded in a 5-coordinate geometry to one La3+, two equivalent Ru+2.25+, and two equivalent P1- atoms. There are one shorter (2.30 Å) and one longer (2.34 Å) P–P bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaRu by Materials Project

RuTa is Tetraauricupride structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ta is bonded in a body-centered cubic geometry to eight equivalent Ru atoms. All Ta–Ru bond lengths are 2.76 Å. Ru is bonded in a body-centered cubic geometry to eight equivalent Ta atoms.

36 MATERIALS SCIENCE↗