Effects of phosphorus modification on the catalytic properties and performance of CuCeZr mixed metal catalyst for simultaneous removal of CO and NOx

Abstract

CO oxidation and selective catalytic reduction of NOx using NH3 (NH3-SCR) have been profoundly studied to eliminate CO and NOx by catalytic routes, respectively. However, the research about proceeding above two reactions together over a single catalyst has not ever been reported for now. Herein, we demonstrate one phosphorus-modified CuCeZr catalyst for the simultaneously catalytic removal of CO and NOx, which realizing up to 90% conversion of both CO and NOx in the temperature of 200–350 °C. Based on the physical–chemical characterizations, it is believed that the introduced phosphorus has a closer affinity with Ce and Zr than Cu. More importantly, phosphorus modification achieves a trade-off between redox ability and surface acidity over the CuCeZr catalyst, which is beneficial to suppress the over-oxidation of NH3 during SCR process. DRIFTS analyses suggest that the SCR reaction mainly proceeds through the Eley-Rideal mechanism, and the carbonate species originated from absorbed CO and surface lattice oxygen are proved to be the key intermediate species during CO oxidation. This work creates a pioneer on realizing CO oxidation and NH3-SCR reactions on a single catalyst simultaneously, providing a novel strategy for flue gas pollutants synergistic control.