Construction of CuO-based composite oxide with high-efficiency performance in catalytic degradation of toluene and chlorobenzene.

Volatile organic compounds (VOCs) are key air pollution control targets. Catalytic combustion technology for VOCs focuses on developing a catalyst system with high catalytic degradation activity, selectivity and stability. In this study, a series of binary composite oxides CuMO (where M was Zr, Nb, Ti, W, Si or Ba) were synthesized by salicylic acid based sol-gel method. Their structures and physicochemical properties were analyzed systematically by different characterization methods, and the degradation performance of catalysts for mixed contaminants (500 ppmv toluene and 500 ppmv chlorobenzene) was studied. The results showed that all CuMO catalysts were mesoporous structure. It was worth noting that the monoclinic phase CuO and tetragonal phase ZrO2 in the CuZrO catalyst were mixed at the nanoscale to form nanomaterials. The catalytic degradation of toluene and chlorobenzene followed the order: CuZrO > CuNbO > CuTiO > CuWO > CuSiO > CuO > CuBaO. Among them, the CuZrO catalyst exhibited the highest activity. This result was due to the unique nanostructure of the CuZrO catalyst, wherein its strong acidity and oxidizability played key roles in the catalytic degradation process. In addition, it exhibited good stability during the long-term reaction and the selectivity to CO2 was as high as 99.9 %. It showed broad application potential in the catalytic treatment of VOCs and other thermal catalysis fields.