Atomically dispersed palladium as a borderline case between heterogeneous and homogeneous hydrogenation of olefins

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

DOI:https://doi.org/10.1016/0021-9517(79)90018-6· OSTI ID:6916993

Carturan, G; Strukul, G

Highly dispersed palladium was prepared by reacting diallylpalladium with vitreous supports and reducing with molecular hydrogen. The conversion of 1-hexene, 1-heptene, cyclohexene, 1-octene, 2-methyl-2-butene, and cyclooctene on the most active of these catalysts, which had a palladium particle size distribution of 2-20 A., was independent of olefin concentration, which is characteristic of heterogeneous catalysis, was apparently controlled by the rate of hydrogen activation, and had rate constants which decreased in the above order of olefins. The dependence of the catalytic activity on the olefin species suggested that bond formation between olefin and palladium precedes the hydrogen activation, as in homogeneous catalysis. The hydrogenation of 1,5-cyclooctadiene, 1,3-cyclooctadiene, dicyclopentadiene, 1,4-octadiene, and 1,7-octadiene proceeded in two pseudo-zero-order steps without isomerization during the first step. The ratios of the first and second step rate constants were always Vertical Bar3:Vertical Bar3: 1, were independent of palladium particle size and concentration, and were higher for cyclic than linear dienes.

• Research Organization: Univ. Padova
• OSTI ID: 6916993
• 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
ALKENES
HYDROGENATION
CATALYSTS
CHEMICAL PREPARATION
PALLADIUM
DISPERSIONS
CATALYST SUPPORTS
CHEMICAL REACTION KINETICS
EXPERIMENTAL DATA
PARTICLE SIZE
CHEMICAL REACTIONS
DATA
ELEMENTS
HYDROCARBONS
INFORMATION
KINETICS
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PLATINUM METALS
REACTION KINETICS
SIZE
SYNTHESIS
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties
400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)