Excellent activity caused by dielectric barrier discharge (DBD) plasma activation for selective catalytic reduction with propylene (C3H6-SCR): Insight into the low temperature catalytic behavior of Mn/ZSM-5 catalysts

For investigation of the low temperature catalytic behavior of C3H6-SCR, a series of Mn/ZSM-5 catalysts were synthesized by different activation and preparation methods for the first time. Under the simulated lean burn condition (5% O2) of actual diesel engines, more than 96% NO conversion was observed at 120–270 °C with the space velocity of 30,000 h−1 on the 7Mn/ZSM-5-CPM-DBD catalyst. The results showed that the excellent low temperature C3H6-SCR of 7Mn/ZSM-5-CPM-DBD catalyst was the shared effect between Brönsted acidity (hydroxyl) and oxygen vacancy on the surface, rather than the separate effect. Besides, the Mn/ZSM-5 catalysts with DBD plasma activation could generate higher dispersion of active species Mn, larger pore size, more abundant oxygen vacancies, and less destructive to zeolite than traditional calcination activation characterized by XRD, SEM, HR-TEM, EDS-mapping, ICP, BET, TG-DTA, XPS, and Py-FTIR. The study expects to shed more light on the nature of the surface active sites of Mn/ZSM-5 in low temperature C3H6-SCR, and the development of novel preparation method for the synthesis of highly active catalysts of low temperature C3H6-SCR.