A highly efficient bi-functional zeolite catalyst for low temperature catalytic cracking of n-octane to produce propylene: Joint contribution of nanogold and dealumination

With respect to catalysis, the pursuit of low reaction temperatures has received continuous efforts for developing energy efficient and environmentally friendly processes. In this study, the significant promotion in the catalytic cracking performance of n-octane at low temperatures of 260–460 °C over Au/ZSM-5 catalysts was obtained via the joint contribution of dealumination and Au species. A 63.5% propylene selectivity and 100% n-octane conversion were obtained over the optimized catalyst at 410 °C. The higher propylene yield was attributed to an increase in the concentration of Brønsted acids and a decrease in that of Lewis acids, as well as synergy between acid sites and Au species. The positive effect of Au species during dehydrogenation at lower temperatures was verified, and electron transfer from Au to the zeolite framework was proposed.