Ti and Si doping as a way to increase low temperature activity of sulfated Ag/Al₂O₃ in H₂-assisted NH₃-SCR of NO_x

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• 作者：Dmitry E. Doronkin ; Sebastian Fogel ; P盲r Gabrielsson ; Jan-Dierk Grunwaldt ; S酶ren Dahl
• 关键词：Ag/Al2O3 ; Doping ; NOx SCR ; Sulphur tolerance ; X-ray absorption spectroscopy
• 刊名：Applied Catalysis B: Environmental
• 出版年：27 April, 2014
• 年：2014
• 卷：148-149
• 期：Complete
• 页码：62-69
• 全文大小：1363 K

文摘

Ag/Al₂O₃ catalysts modified by Si, Ti, Mg and W were studied to obtain higher NO_x SCR activity and potentially also higher SO₂ resistance than the pure silver-based catalyst for automotive applications. Addition of Ti or Si to the alumina support leads to a better NO_x removal at low temperature i.e. reduces the SCR onset temperature by about 10 掳C under the applied conditions. However, it does not increase the SO₂ resistance. The catalysts and the supports have been characterized by BET, conventional and synchrotron XRD, X-ray absorption spectroscopy during temperature-programmed reduction (XAS-TPR) and temperature-programmed desorption of ammonia (NH₃-TPD). The obtained results suggest a better silver dispersion and better regeneration capability in the case of Ti- and Si-modified Ag/Al₂O₃ catalysts.