Adsorption and temperature-programmed desorption of hydrogen with dispersed platinum and platinum-gold catalysts

Journal Article · Tue May 01 00:00:00 EDT 1979 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(79)90012-5· OSTI ID:6682680

Anderson, J R; Foger, K; Breakspere, R J

Adsorption and temperature-programmed desorption of hydrogen with dispersed platinum and platinum-gold catalysts was studied with 0.9-3Vertical Bar3< platinum on silica gel, aerosil, sodium and lanthanum Y zeolites, and ..gamma..-alumina, and on aerosil-supported gold-platinum alloys containing 2, 10, 24, 33, and 85Vertical Bar3< gold. Surface enrichment with gold in the alloy systems, as derived from hydrogen adsorption data and predicted from surface enrichment theory and electron microscopic measurements of particle size, were in good agreement, which indicated that equilibrium was achieved by the thermal treatment (oxygen at 573/sup 0/K, hydrogen at 620/sup 0/K, repeated cycles) used. Hydrogen spillover to gold was observed at the higher hydrogen pressures tested on the alloys with high gold content, and to the zeolite supports. The temperature-programed desorption profiles were independent of gold content, which indicated that gold acts only as diluent, and that isolated surface platinum atoms become populated with hydrogen atoms either by hydrogen atom spillover from platinum ensembles to gold and from the gold to the isolated platinum, and/or by adsorption of a molecule directly on the isolated platinum and chemisorption of one H atom at an adjacent gold atom. The distribution of surface platinum ensembles was evaluated by a computer simulation method.

• Research Organization: Univ. Melbourne
• OSTI ID: 6682680
• Journal Information: J. Catal.; (United States), Vol. 57:3
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DISTRIBUTION
COMPUTERIZED SIMULATION
GOLD
ALLOYS
PLATINUM
CATALYST SUPPORTS
CATALYSTS
EXPERIMENTAL DATA
HYDROGEN
PARTICLE SIZE
PRESSURE EFFECTS
QUANTITY RATIO
SORPTIVE PROPERTIES
SURFACE PROPERTIES
TEMPERATURE EFFECTS
DATA
ELEMENTS
INFORMATION
METALS
NONMETALS
NUMERICAL DATA
PLATINUM METALS
SIMULATION
SIZE
TRANSITION ELEMENTS
400201* - Chemical &amp; Physicochemical Properties