Excellent MCM‐49 Supported CeCuO_x Nanocatalyst with Ultrawide Operating Temperature Window and Strong Anti‐Alkali Ability for NH₃‐SCR

Abstract

NOx is a common atmospheric pollutant, and NH3‐SCR technology efficiently purifies it. CeCuOx binary‐oxide nanoparticles were synthesized and loaded onto acid MCM‐49 molecular sieve with a large specific surface area to increase acid sites and disperse active sites of the catalyst. The optimized 35 % CeCu/MCM‐49 catalyst effectively purified over 80 % of NOx in the temperature range of 200–500 °C and demonstrated excellent resistance to alkali metals, such as K, Na, and Ca. Even after K poisoning, it still removed over 80 % of NOx in the range of 200–450 °C. Various characterization methods, including XRD, FT‐IR, TEM, and N2 isotherm adsorption‐desorption tests, confirmed the structure of the catalyst remained intact after poisoning with no substance change, nor agglomeration of nanoparticles. NH3‐TPD and H2‐TPR confirmed that the catalyst had effective acidity and redox capacity that were not affected by alkali metals. In‐situ DRIFTs showed that the catalytic reaction predominant mechanism shifted from L−H to E−R mechanism after poisoning. This study provides valuable insights into the development of high‐performance Ce‐based NH3‐SCR catalysts with alkali metal resistance.