Role of Ni species in ZnO supported on Silicalite-1 for efficient propane dehydrogenation

Abstract

Propane dehydrogenation (PDH) is one of the most effective technologies to produce propene. Non-noble zinc-based catalysts have paid increasing attention because of low cost and nontoxic, compared with industrial Pt and Cr-based catalysts. However, they often suffer from limited catalytic activity and poor stability. Here, we introduced moderate Ni into ZnO supported Silicalite-1 zeolite to increase catalytic activity and stability simultaneously. Zn 2+ was the definite active site and NiZn alloy facilitated the sluggish H recombination into H 2 via reverse spillover. Furthermore, the introduction of Ni increased Lewis acid strength caused by electron transfer from ZnO to NiZn alloy, contributing to improved stability. For resulted 0.5NiZn/S-1, propene formation rate was 0.18 mol C 3 H 6 ·(g Zn) −1 ·h −1 at 550 °C, which was above 1.5 times higher than that over Zn/S-1 without Ni. Under stability test, the deactivation of 0.5NiZn/S-1 was 0.019 h −1 , which was only 1/10 of that over Zn/S-1.