Characterization of silica-supported Ru-Ag and Ru-Au bimetallic catalysts by hydrogen chemisorption and NMR of adsorbed hydrogen

Journal Article · Tue May 01 04:00:00 EDT 1990 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(90)90156-E· OSTI ID:6437714

Wu, X; Gerstein, B C; King, T S ^[1]

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1. Iowa State Univ., Ames (USA)

Silica-supported Ru-Ag and Ru-Au bimetallic catalysts were studied by hydrogen chemisorption and by nuclear magnetic resonance (NMR) of adsorbed hydrogen. Both techniques yielded nearly the same capacity for hydrogen chemisorption on both series of bimetallic catalysts. A small difference measured by the two techniques was attributed to hydrogen spillover from ruthenium onto the silica support. This effect of hydrogen spillover was less pronounced in Ru-Ag/SiO{sub 2} than in Ru-Au/SiO{sub 2}, as indicated by the longer spin-lattice relaxation times of the silanol proton. The results of these studies are used to infer that a stronger interaction exists between silver and ruthenium than between gold and ruthenium in the supported bimetallics. Both NMR results and volumetric chemisorption results show that residual chlorine inhibits the hydrogen chemisorption capacity of the Ru/SiO{sub 2} catalyst and Ru-Au/SiO{sub 2} bimetallic catalysts. The variation of the adsorbed hydrogen chemical shift with chlorine coverage indicates an electronic interaction that is due to chlorine adsorption. A direct comparison between clean Ru-Cu/SiO{sub 2} (from a previous study), Ru-Ag/SiO{sub 2}, and Ru-Au/SiO{sub 2} bimetallic catalysts was made to illustrate the varying degrees of interaction between ruthenium and copper, silver, or gold. 35 refs.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6437714
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 123:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
BIMETALS
CATALYST SUPPORTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
CHLORINE
COPPER
ELEMENTS
GOLD
HALOGENS
HYDROGEN
INHIBITION
MAGNETIC RESONANCE
METALS
NONMETALS
NUCLEAR MAGNETIC RESONANCE
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
RELAXATION
RELAXATION TIME
RESONANCE
RUTHENIUM
SEPARATION PROCESSES
SILICON COMPOUNDS
SILICON OXIDES
SILVER
SORPTION
SORPTIVE PROPERTIES
SPIN-LATTICE RELAXATION
SURFACE PROPERTIES
TRANSITION ELEMENTS