Cu/SSZ-13 and Cu/SAPO-34 catalysts for deNOx in diesel exhaust: Current status, challenges, and future perspectives

Copper-exchanged SSZ-13 and SAPO-34 (Cu/CHA) zeolites catalysts have been commercially utilized for selective catalytic reduction (SCR) of NOx by NH3. Despite the significant advances in both fundamental research and industrial application have been made, the limited catalytic activity at low exhaust temperatures, the challenges of sulfur/alkali (alkaline) metal/phosphorus poisoning and hydrothermal deactivation have spurred the development of new generation NH3-SCR catalysts. This paper reviews the recent progress for Cu/CHA in regard to zeolite synthesis, the latest SCR reaction mechanisms, the poisoning and hydrothermal deactivation mechanisms, more importantly, corresponding poisoning-resistant and protective strategies are also proposed, some issues that still need to be addressed are also highlighted. We hope to construct a linkage between next generation of catalysts and real-world applicable demands to meet the escalating emission regulations in the near future.