A facile one-pot synthesis of hierarchically porous Cu(I)-ZSM-5 for radicals-involved oxidation of cyclohexane

Abstract

An extraordinarily high catalytic performance of up to 28% cyclohexane conversion and above 93% selectivity for cyclohexanone and cyclohexanol in the cyclohexane oxidation has been achieved under mild conditions by using copper-doped hierarchically micro/mesoporous zeolite ZSM-5, which has been fabricated by a facile one-pot hydrothermal synthetic process at a relatively low hydrolysis temperature. The excellent catalytic activity was ascribed to the highly dispersed framework copper ions (Cu+/Cu2+) as catalytic active sites and the hierarchically porous structure to provide the fast diffusion pathway for reactant/product molecules. The presence of the framework Cu(I) was proposed to promote the decomposition of H2O2 and the formation of radicals HO, and thus accelerate the selective oxidation of cyclohexane. More importantly, the synthesized catalyst showed excellent recyclable properties, demonstrating the high catalytic stability and future application prospect of such hierarchical heterogeneous catalysts in chemical industry.