Cu-promoted Zirconia Catalysts for Non-Oxidative Propane Dehydrogenation

Bulk ZrO2 has shown high activity and selectivity for propane dehydrogenation (PDH). Its catalytic performance can be enhanced by substitution of the Zr ions with suitable dopant ions. In this study, a series of Cu-doped ZrO2 metal oxides (CuZrO-x) have been prepared using the co-precipitation method and the effects of the amount of dopant on their properties have been investigated. The appropriate amount of Cu dopant promotes the creation of oxygen vacancies and coordinatively unsaturated Zr-cus(4+) sites, active sites for PDH; however, excess Cu forms bulk CuO in the CuZrO-x catalysts resulting in decreased activity. The catalytic activity for PDH is closely correlated to the amount of weak Lewis acid sites in CuZrO-x. Moreover, a comparison of the CuZrO-x properties with those of Cu-impregnated ZrO2 has shown that the amount of acid sites and therefore, the catalytic performance, depends on the doping method.