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采用水相法制备了Ce、W、Ti复合氧化物催化剂并用于氨选择性催化还原NO(NH_3-SCR)过程。TiO_2包裹型Ce-W@TiO_2催化剂表现出最佳的催化活性。205-515℃NO转化率超过90%。SO_2的存在造成所有催化剂低温段NO催化转化率的降低和高温段(425-540℃)NO催化转化率的升高,TiO_2@Ce-W表现出优越的低温抗SO_2性能。通过普通共沉淀法向Ce-W复合氧化物中引入Ti会导致催化剂表面W丰度、酸性位点的减少和低温NO转化率、耐SO_2性能的降低。通过水相法制备的TiO_2包裹型的Ce-W@TiO_2型催化剂,有利于表面W丰度、酸性位点、低温抗SO_2性能和催化活性的提高。
Ce, W, Ti composite oxide catalysts were prepared by aqueous method and used for the selective catalytic reduction of NO (NH 3-SCR). The TiO 2 -based Ce-W @ TiO_2 catalyst showed the best catalytic activity. 205-515 ° C NO conversion over 90%. The presence of SO 2 results in the reduction of the NO catalytic conversion in all catalysts at low temperature and the increase of NO conversion in the high temperature (425-540 ℃). The TiO 2 @ Ce-W exhibits excellent low temperature SO 2 resistance. The introduction of Ti into the Ce-W composite oxide by the common coprecipitation method results in the reduction of W abundance, acid sites and low-temperature NO conversion and SO2 resistance of the catalyst surface. The TiO 2 -type Ce-W @ TiO_2 catalysts prepared by aqueous method are favorable for the enhancement of surface W abundance, acid sites, low temperature resistance to SO 2 and catalytic activity.