Transition metal-containing MFI-based catalysts are widely investigated in NH₃-SCR-DeNO _x and NH₃-SCO. Our review gives a critical overview of the influence of introducing mesopores on the catalyst activity and N₂ selectivity as well as the strategies for the development of ZSM-5 based catalysts with enhanced catalytic lifetime, supported by the investigations of reaction mechanisms.

Abstract

Transition metal-containing MFI-based catalysts are widely investigated in the selective catalytic reduction of NO _x with ammonia (NH₃-SCR-DeNO _x ), and the selective catalytic oxidation of ammonia (NH₃-SCO) into nitrogen and water vapor. While MFI-based catalysts are less intensively studied than smaller pore zeolites (i. e., chabazite, CHA) they are still used commercially for these processes and are of great interest for future study in particular to better understand structure-activity relationships. Hierarchically porous MFI catalysts (containing both micropores and mesopores) often show enhanced catalytic properties compared to conventional (microporous) materials in both NH₃-SCR-DeNO _x and NH₃-SCO. Thus, a critical overview of the current understanding of the salient physico-chemical properties that influence the performance of these catalysts is examined. Furthermore, strategies for the development of ZSM-5 based catalysts with enhanced catalytic lifetime, supported by the investigations of reaction mechanisms are reviewed and discussed.

The Cover Feature shows the efforts of scientists to modify transition-metal containing MFI topologies to achieve the highest activity and N₂ selectivity for NH₃-SCR-DeNO _x and NH₃ oxidation. MFI-based catalysts are still used commercially for these processes and are of great interest for future study, in particular to better understand structure-activity relationships. In their Review, M. Jabłońska, M. E. Potter and A. M. Beale critically review and discuss the salient physico-chemical properties that influence the performance of these catalysts together with the strategies for the development of ZSM-5 based catalysts with enhanced catalytic lifetime, supported by the investigations of reaction mechanisms.More information can be found in the Review by M. Jabłońska, A. M. Beale et al.