Research progress on the design of zeolite-based core-shell structure catalysts and their reaction mechanism for diesel vehicle exhaust deNO_x

Nitrogen oxides (NO_x) from diesel engine exhaust is one of the main sources of environmental pollution. Zeolite-based NH₃-SCR catalysts have extensively investigated and have shown great promise for the efficient reduction of NO_x because of their excellent NH₃-SCR performance, robust hydrothermal stability and outstanding N₂ selectivity. However, with the increasingly stringent environmental regulations and the implementation of the requirement of “zero emission” of diesel engine exhaust, it is particularly important to develop zeolite-based catalysts with more excellent catalytic activity and anti-poisoning performance, especially core-shell structure catalyst. In this review, we mainly focus on the recent research progress of the core-shell structure zeolite-based catalysts for NH₃-SCR reactions with three commonly used Beta, ZSM-5, and SSZ-13 zeolite as the cores, the reaction mechanism of resistance to hydrothermal aging, sulfur poisoning, hydrocarbon poisoning, and alkali metal poisoning, as well as the future development and application prospects of zeolite-based core-shell structure catalysts.