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

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. Zn2+ was the definite active site and NiZn alloy facilitated the sluggish H recombination into H2 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 C3H6·(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.