Research progress on selective catalytic reduction of NOx by NH3 over copper zeolite catalysts at low temperature: reaction mechanism and catalyst deactivation

Selective catalytic reduction (SCR) system is considered to be the most effective control method for reducing NOx in exhaust gas post-treatment of the diesel engine. Catalysts are the main factors affecting de-NOx efficiency in SCR reactions. In recent years, due to the excellent characteristics of copper zeolite catalysts, they have been widely studied as low-temperature NH3-SCR catalysts. However, the development of low-temperature SCR catalysts with high removal efficiency still faces severe challenges. This paper reviewed the latest research progress with copper zeolite catalysts at low temperature and compared the action mechanism of various copper zeolite catalysts in NH3-SCR reactions. Copper zeolite catalysts were studied from the aspects of catalytic performance, preparation strategy, broadening the operating temperature window, hydrothermal deactivation and resistance to H2O and SO2. Several solutions to the problems existing in low-temperature NH3-SCR reactions were discussed. In addition, this paper also puts forward some views on the future research direction of copper zeolite catalysts. Finally, the summaries and prospects of the development of low-temperature SCR copper zeolite catalysts were presented. Hopefully, more researchers can understand the current research status of copper zeolite catalysts and obtain better research achievements from copper zeolite catalysts in the future. This review could pave the way for similar studies to enable a wider variety of copper zeolite catalysts to be commercially available.

Automated summary

Selective catalytic reduction (SCR) system is considered the most effective control method for reducing NOx in diesel engine exhaust gas. Catalysts play a key role in the de-NOx efficiency of SCR reactions. This paper reviews the recent progress in low-temperature NH3-SCR catalysts using copper zeolite catalysts and discusses the challenges and potential solutions. The summary and future research direction of copper zeolite catalysts for low-temperature SCR are also presented.