Tandem supported Pt and ZSM-5 catalyst with separated catalytic functions for promoting multicomponent VOCs oxidation

Abstract

The painting and electronics industries simultaneously release aromatic compounds and chlorinated organics. The development of catalysts with synergistic control of these pollutants is of great significance to achieve air purification. However, developing active catalysts while maintaining good chlorine resistance remain a huge challenge due to the difficulty of the trade-off between the redox properties and acidity and the production of polychlorinated byproducts. Herein, we introduce a novel tandem PtSn/CeO2&Mn/ZSM-5 catalyst and investigate its catalytic performance for multicomponent volatile organic compounds (VOCs) oxidation. The two individual catalysts, PtSn/CeO2 and Mn/ZSM-5, were used to catalyze two distinct sequential reactions. PtSn/CeO2 catalyzed toluene oxidation to produce CO2 and H2O. Meanwhile, the introduction of SnOx favored the adsorption of trichloroethylene (TCE) molecules that prevented Pt sites from chlorine poisoning and possibly converted adsorbed TCE into intermediates, which were subsequently oxidized deeply by the nearby Mn/ZSM-5. This approach resulted in a remarkable oxidation efficiency for toluene (T90 = 296 °C) and TCE (T90 = 384 °C), with fewer unexpected toxic byproducts (chlorobenzene and 4-chlorotoluene). Furthermore, the tandem catalyst possessed excellent chlorine and water resistances. In conclusion, the above findings provide new insights into the design and/or syntheses of advanced catalysts for widespread VOCs pollution control.