Enhanced activity of Pd/TiO/sub 2/ catalysts for the CO/H/sub 2/ reaction in the absence of strong metal-support interactions (SMSI)

Journal Article · Sun Apr 01 04:00:00 EST 1984 · J. Catal.; (United States)

OSTI ID:6726815

Bracey, J D; Burch, R

Pd/TiO/sub 2/ and Pd/SiO/sub 2/ catalysts have been prepared and reduced at different temperatures. The dispersion of the Pd has been determined by adsorption of H/sub 2/ and CO, and the catalytic activity has been determined for the hydrogenolysis of ethane and for the CO/H/sub 2/ reaction. It is found that the Pd/SiO/sub 2/ catalysts, and the Pd/TiO/sub 2/ catalyst reduced at low temperatures, exhibit normal chemisorption and catalytic properties. Pd/TiO/sub 2/ catalysts reduced at high temperatures have much lower capacity to adsorb H/sub 2/ or CO and much lower specific activities for the hydrogenolysis of ethane, which is consistent with the presence of a strong metal-support interaction (SMSI). For the CO/H/sub 2/ reaction it is found that all the Pd/TiO/sub 2/ catalysts have enhanced activity for the CO/H/sub 2/ reaction, irrespective of whether or not strong metal-support interactions are operative. It is concluded that the high activity of titania-supported catalysts in the CO/H/sub 2/ reaction is not due to SMSI. Instead it is proposed that the role of the support is to create new active sites at the interface between the metal and the support. These new sites have the capacity to adsorb, or assist in the adsorption of, CO. It is suggested that a similar model may account for the observed effects of other, irreducible, supports, where enhanced activity may also be obtained.

• Research Organization: Univ. of Reading, England
• OSTI ID: 6726815
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 86:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020500* -- Petroleum-- Products & By-Products
090121 -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
ALKANES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
ETHANE
HYDROCARBONS
HYDROGEN
HYDROGENATION
METALS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PALLADIUM
PLATINUM METALS
SYNTHESIS
TRANSITION ELEMENTS