Enhanced catalytic elimination of typical VOCs over ZnCoOx catalyst derived from in situ pyrolysis of ZnCo bimetallic zeolitic imidazolate frameworks

In this work, ZnCoOx catalysts were prepared using in situ pyrolysis of ZnCo bimetallic zeolitic imidazolate frameworks (ZIFs), which were rationally designed on the basis of a metal ion doping strategy. The derived Zn0.05CoOx with proper doping of Zn (Zn/Co molar ratio of 0.05) exhibited superior catalytic activity and durability towards catalytic elimination of different volatile organic compounds (VOCs) including benzene, toluene and cyclohexane under simulated real-exhaust conditions. Both Brønsted and Lewis acid sites were beneficial for cyclohexane degradation, whereas only Lewis acid sites were responsible for eliminations of benzene and toluene. In addition, the effect of chemical structures of VOCs on their catalytic elimination over Zn0.05CoOx was explored. Compared to benzene and toluene, cyclohexane molecule was more easily eliminated, attributed to strong adsorption onto catalyst and special chemical structure of cyclohexane. The obtained results can provide new strategy for rational design of highly efficient catalytic materials for eliminating VOCs.