Oxidative Dehydrogenation of Methylcyclopentane to Methylcyclopentadiene-1,3 Over Modified Zeolite Catalysts

Abstract

Selective C−C-and C−H-bond activations are an important catalytic process to produce various valueadded hydrocarbons oxidative dehydrogenation processes. For producing desired product with a high yield control of reaction pathway through the design of catalyst, fundamental understanding and clarification of reaction mechanism are prerequisite. In this work, we designed heterogeneous catalysts by combining {Cu 2+ (0.5 mas.%), Zn 2+ (0.2 mas.%), Co 2+ (0.1 mas.%), Cr 3+ (0.1 mas.%)} and clinoptilolite zeolites particles for oxidative dehydrogenation reaction of methylcyclopentane. Depending on the catalyst combination, the reaction pathways of dehydrogenation, ring-opening with isomerization, and ringenlargement with hydrogenation and dehydrogenation of C 5 -cyclic ring to C 6 -cyclic ring (i.e., cyclohexane and benzene) can be controlled to produce various products with high yields. The conversion of methylcyclopentane was investigated over HY zeolite at 360 0 C. Catalytic activity of the clinoptilolite in the reaction of selective oxidative dehydrogenation of methylcyclopentane into methylcyclopentadiene has been measured experimentally. Addition of Zn increases the stability of catalytic activity and induces distinct selectivity changes. When the Zn content is increased, dehydrogenation of methylcyclopentane to methylcylopentadiene goes through a maximum and deep dehydrogenation of methylcylopentane to benzene remains roughly constant. This study would provide practical and fundamental insight for design of heterogeneous catalyst for controlling reaction pathways.