Effect of oxidation-reduction cycling on C sub 2 H sub 6 hydrogenolysis: Comparison of Ru, Rh, Ir, Ni, Pt, and Pd on SiO sub 2

Journal Article · Wed Feb 01 04:00:00 EST 1989 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(89)90040-7· OSTI ID:7128553

Gao, S; Schmidt, L D ^[1]

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1. Univ. of Minnesota, Minneapolis (USA)

Activities of C{sub 2}H{sub 6} hydrogenolysis on 5% Ru, Rh, Ni, Ir, Pt and Pd supported on SiO{sub 2} are compared as functions of oxidation and reduction treatments. It is shown that activities after oxidation and low-temperature reduction vary by a factor of {approximately}10{sup 6} between metals in the order Ru > Rh > Ir {approximately} Ni > Pt > Pd. Annealing at high temperatures causes all rates to decrease, with the largest changes ({approximately}10{sup 3}) on Ru and Rh and smaller changes (3 to 30) on other metals. Most rates do not change significantly with reaction time, but Ir rapidly deactivates due to carbon formation. These results correlate with the ability of each metal to retain the high-activity, low-coordination sites produced by oxidation and low-temperature reduction, and for Pt, the inability to form the oxide. Thus, Ni and Pd exhibit small changes because the metal surfaces anneal by 200 C, and the more refractory Ru, Rh, and Ir can be retained in the high-activity state during hydrogenolysis.

• OSTI ID: 7128553
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 115:2; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
ALKANES
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
DEHYDROGENATION
ELEMENTS
ETHANE
HYDROCARBONS
IRIDIUM
METALS
MINERALS
NICKEL
ORGANIC COMPOUNDS
OXIDATION
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PALLADIUM
PLATINUM
PLATINUM METALS
REDUCTION
RHODIUM
RUTHENIUM
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SYNTHESIS
TIME DEPENDENCE
TRANSITION ELEMENTS