Promotional effect and mechanism of the modification of Ce on the enhanced NH3-SCR efficiency and the low temperature hydrothermal stability over Cu/SAPO-34 catalysts

This study focuses on co-cations modified copper based molecular sieve catalyst CuCe/SAPO-34. The SCR performance and low temperature hydrothermal stability of Cu/SAPO-34 CuCe/SAPO-34 before after 70 ? aging were evaluated to conclude the impact Ce structure mechanism NH3-SCR reaction. For fresh samples, showed higher catalytic activity at whole range, especially below 250 above 400 in comparison pure Cu/SAPO-34. aged catalysts, exhibited efficiency than Cu/SAPO-34, more 80 % NOx conversion 175 450 ?, whereas, that was only 225 for effect co-cation physicochemical structure, acidity, redox capacity, Cu species migration, framework samples comprehensively characterized by NH3-TPO, NO-TPO, H2-TPR, NH3-TPD, BET, XRD XPS. addition decreased amount CuxOy species, increased Cu2+ sites, improve ability active sites. After aging, remained structural integrity CHA framework. protected ions prevented dealumination process aging. Furthermore, situ DRIFTS indicated that, with doping, sites monodentate nitrates adsorbed formed, resulting excellent stability. In conclusion, modification could catalyst.