Selectivity of cyclopropane reactions on copper-nickel alloy powers

The selectivity of cyclopropane hydrogenation and hydrogenolysis on copper-nickel alloy catalysts was investigated. Alloy powders were prepared by a modified Best-Russell method and the homogeneity of these alloys was confirmed by magnetic measurements. The catalytic activity and selectivity of each of the alloys were determined in a pulse microreactor. The samples were also analyzed for hydrogen chemisorption and nitrogen BET surface areas using conventional adsorption techniques. The samples were homogeneous in that no unalloyed nickel was detected. Copper had a promoting effect on nickel for both the hydrogenation and the hydrogenolysis of cyclopropane. The hydrogenation rate constant at 150°C of some of the alloys was 15 times that of pure nickel; the hydrogenolysis rate constant of these same alloys was ten times that of pure nickel. This behavior was found to be consistent with the Localized Bond Theory of Catalysis. The nitrogen BET surface areas varied around 1 m[superscript 2]/g, as expected; however, the hydrogen chemisorption values were lower than expected and followed no definite trend. Differences in reduction technique are suggested as the cause for this behavior although the reduction technique used appeared to result in bulk-surface homogeneity.