New Mn-TiO2 aerogel catalysts for the low-temperature selective catalytic reduction of NOx

A new series of Mn-based catalysts (Mn-TiO2, Ce-Mn-TiO2, Mn-TiO2-SO42–, and Ce-Mn-TiO2-SO42–) were successfully elaborated using the sol–gel method associated with supercritical drying approach for low-temperature NO-SCR by NH3. The physicochemical properties aerogel powders examined XRD, N2-Physisorption at 77 K, NH3-TPD, H2-TPR, DRUV-Vis spectroscopy. It was shown that all develop essentially diffraction peaks TiO2 anatase phase are characterized a nanometer size (ranging between ~5 9 nm), developed mesoporous texture, high surface area (SBET > 104 m2/g) large porosity (VPT 0.24 cm3/g). incorporation Ce and/or SO42– influences differently structural, textural, acidic, redox Mn-derived consequently affects their SCR activity. High NO conversions (>75%) into N2O obtained low temperatures (150–270 °C) over Mn-TiO2 Ce-Mn-TiO2 systems. addition sulfate modifies nature Mn species noticeably reduces reactivity (T < 300 °C). However, it induces, thanks to contribution many strong acid sites, substantial increase conversion N2 higher leading highly active N2-selective Mn-TiO2-SO42– Ce-Mn-TiO2-SO42– sulfated catalysts. Above 90% (100%) reached, in NH3, catalyst, 450–500 °C temperature range.