Alloy formation and metal oxide segregation on Pt-Re/. gamma. -Al/sub 2/O/sub 3/ catalysts as investigated by temperature-programmed reduction

Journal Article · Mon Oct 15 04:00:00 EDT 1979 · J. Catal.; (United States)

OSTI ID:6463175

Wagstaff, N; Prins, R

Catalysts resembling reforming catalysts were prepared to contain finely dispersed 0.75% Pt, 0.7% Re, or 0.35% Pt plus 0.1-2% Re on chlorided ..gamma..-alumina. The catalysts were dried in an oxidizing atmosphere and studied by temperature-programed reduction. Up to a Re/Pt ratio of 0.6:1 the metals were completely reduced in hydrogen below 255/sup 0/C, i.e., the platinum catalyzed rhenium reduction. A small amount of added water (< 50 ppm) also promoted rhenium reduction. Segregation of the metals occurred in oxygen above 200/sup 0/C, but at 100/sup 0/C, the rate of segregation was slow. These results suggested that under reforming conditions, Pt-Re catalysts are completely reduced bimetallic clusters. The mechanisms of reduction, cluster formation, and oxidative segregation are discussed.

• Research Organization: Shell Research B.V.
• OSTI ID: 6463175
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 59:3; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical &amp; Physicochemical Properties
ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
KINETICS
METALS
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PLATINUM
PLATINUM METALS
QUANTITY RATIO
REACTION KINETICS
REDUCTION
RHENIUM
SEGREGATION
SYNTHESIS
TEMPERATURE EFFECTS
TRANSITION ELEMENTS