Insights into novel mesoporous Cu-SAPO-34 with enhanced deNOx performance for diesel emission control

Abstract The formation of ammonium sulfates and existence of mass transportation limits during selective catalytic reduction of NOx with NH3 (NH3-SCR) are severely affecting the deNOx performance of small pore zeolites. Herein, a novel hierarchical porous Cu-SAPO-34-Meso zeolite rich with mesopores was synthesized by one pot dual-template strategy. Cu-SAPO-34-Meso exhibited remarkable deNOx performance and broaden temperature window compared with Cu-SAPO-34-Con without mesopores, especially at low reaction temperature, which should be attributed to the mesopores in Cu-SAPO-34-Meso can accelerate the transportation of the reactants and this has been confirmed by the diffusion calculation. Even exposed on SO2 feed gas, Cu-SAPO-34-Meso also displayed better SO2 resistance compared with Cu-SAPO-34-Con. The in situ DRIFTS revealed that the enhanced SO2 tolerance might be attributed to Cu-SAPO-34-Meso with mesopores could prevent the sulfur species blocking the pores and promote the decomposition of the sulfur species quickly. Therefore, the novel Cu-SAPO-34-Meso catalyst might be a good candidate for real diesel emission control application.