Unraveling Active Ni Sites over Dealuminated β Zeolite for Propane Dehydrogenation

Propane dehydrogenation (PDH) is a very important and efficient propylene production process. Currently, it is a challenge to design a catalyst that can replace precious Pt and toxic Cr. Ni species are widely used in reactions for the activation of C–C and C–H bonds, but making Ni species active sites for alkane dehydrogenation is a challenge. In this paper, a series of catalysts with different Ni loadings were impregnated onto dealuminated β zeolite, and it was observed that low loadings of the metal could improve Ni dispersion and produce a high amount of Lewis acid sites, thus inhibiting the side reactions during the PDH process. The characterization results demonstrated that Ni species at low loadings were successfully introduced into vacancy defects over the dealuminated β zeolite. Moreover, good dispersion of Ni sites and excellent reactivity were obtained, with 42% initial propane conversion and a high propylene generation rate of 0.8 g–1·h–1, which was higher than those of many other metal catalysts. This study provides new ideas for the development of economical and environmentally friendly PDH catalysts.