Simultaneous catalytic elimination of CO, toluene and NH3 over multifunctional CuCeZr based catalysts

Catalytic oxidation technology is a promising strategy to eliminate carbon monoxide (CO), volatile organic compounds (VOC) and other emissions from industrial boilers and to address ammonia (NH3) escape. Herein, we demonstrate the potential of copper-cerium-zirconium mixed oxides or those supported on TiO2 or ZSM-5 substrates for the simultaneous catalytic removal of CO, toluene and NH3. Among them, CuCeZr/ZSM-5 exhibits the best co-processing ability for mixed gases. In situ infrared spectroscopy analyses suggest that there is a competitive adsorption among CO, toluene and NH3, and the inhibition is in descending order of toluene＞CO＞NH3. Based on the physical-chemical characterizations, the Cu-Ce interfacial structure plays an important role in CO ignition at low temperatures. More importantly, the abundant acidic sites on the ZSM-5 support can improve the stability of adsorbed NH3 at high temperatures, resulting in the best NH3 catalytic oxidation performance of CuCeZr/ZSM-5 with no secondary pollutants of NOx. This study provides a strategy for the catalyst design to eliminate multiple pollutants targeting the properties of pollutants.