Effect of acidic components (SO42- and WO3) on the surface acidity, redox ability and NH3-SCR activity of new CeO2-TiO2 nanoporous aerogel catalysts: A comparative study

Selective catalytic reduction (SCR) of nitrogen oxide (NO) by ammonia (NH3) was studied in this work over new sulfate (SO42-) or tungsta (WO3) modified CeO2-TiO2 aerogel catalysts. The systems were elaborated via sol gel method then characterized by: XRD, N2-Physisorption at 77 K, DRUV–vis, NH3-TPD and H2-TPR. It revealed that the nature acidic components influences differently texture, surface oxygen concentration, acidity, reducibility NH3-SCR activity Ce-based Hence, incorporation modifies Ce species, improves their dispersion through Ce-SO42- interactions and, particularly, generates strong acid sites which display superior performance high temperature NO (NO conversion into N2 > 90 % between 450 500 °C CeO2-TiO2-SO42- catalyst). However, addition affects slightly acidity catalyst but it induces creation more reactive redox its (mainly due to existence W-Ce interactions) leading highly active WO3-CeO2-TiO2 system for low reaction with above 320 400 °C.