Anatase-reinforced PtZn@Silicalite-1 structured catalysts boosting propane dehydrogenation

Abstract

Structured catalysts exhibit the advantages of high diffusion efficiency and low heat transfer resistance, which have attracted increasing attention to non-adiabatic gas–solid process. However, the metal-supported coating catalysts face the problems of weaker bond strength and severe sintering, especially under the conditions of large flow rate and high temperature. Herein, metal@Silicalite-1 structured catalysts with high adhesion and thermal stability were successfully prepared by hydroxylating the substrate with anatase. Rich surface Ti-OH significantly strengthened the adhesion stability of the zeolite coating. In propane dehydrogenation reaction, the optimized PtZn@S-1-15Ti showed a high specific activity of 49.6 mol_C3H6·mol_Pt⁻¹·s⁻¹ with propylene selectivity above 99% at 600°C. The introduction of anatase accelerated the aggregation of silicon sources and induced nucleation with growth content of zeolite increased by 3.6 times. It breaks the inherent contradiction between high loading amount and strong binding ability of coated catalysts, which broadens the avenues for industrial applications.