金属修饰对Cu-SAPO-34催化剂NH3-SCR反应性能的影响  

Effect of Metal Modification on NH3-SCR Reaction Performance of Cu-SAPO-34 Catalyst

作　　者：王楚楚 徐倩 王丽[1] 詹望成[1] 郭杨龙[1] 郭耘[1] Wang Chuchu;Xu Qian;Wang Li;Zhan Wangcheng;Guo Yanglong;Guo Yun(Key Laboratory for Advanced Materials and Research Institute of Industrial Catalysis,School of Chemistry&Molecular Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学化学与分子工程学院工业催化研究所,上海200237

出　　处：《稀有金属》2020年第2期159-165,共7页Chinese Journal of Rare Metals

基　　金：上海市浦江人才计划项目(17PJD012)资助。

摘　　要：采用浸渍法引入稀土元素Ce和过渡金属Mn,考察了其对Cu-SAPO-34分子筛催化剂用于氨选择性催化还原氮氧化物(NH3-SCR)反应性能的影响;并运用多种手段,如X射线衍射(XRD)、 N2吸-脱附、 X射线光电子能谱(XPS)、氢气程序升温还原(H2-TPR)、氨气程序升温脱附(NH3-TPD)等对催化剂的物理和化学性质进行表征。稀土元素Ce的引入有效提高了Cu-SAPO-34分子筛催化剂的在高温区(375~570℃)对氮氧化合物的脱除能力;与之相反,过渡金属Mn的引入则抑制了催化剂的在高温区的反应性能。催化剂表征结果表明Ce的引入有效提高了催化剂表面的酸量、表面Cu+/Cu2+比例,以及对NO的吸附和氧化能力;Mn的引入增加了Cu-SAPO-34分子筛催化剂表面非活性中心CuO物种浓度的同时也降低了催化剂表面总酸的浓度。Mn促进高温下NH3氧化性能的提高,从而降低了参与NH3-SCR反应中NH3的浓度,导致高温NH3-SCR反应性能降低。Rare earth Ce and transition metal Mn introduced by impregnation method were investigated over Cu-SAPO-34 molecular sieve catalyst for selective catalytic reduction of nitrogen oxides with NH3(NH3-SCR). Meanwhile the physicochemical propertiesof the catalysts were characterized by X-ray diffraction(XRD), N2 adsorption/desorption, X-ray photoelectron spectroscopy(XPS), hydrogen temperature program reduction(H2-TPR), ammonia temperature program desorption(NH3-TPD). The introduction of Ce effectively improved the high temperature(375~570 ℃) activity of the catalyst for NOx removal, while the addition of Mn suppressed the high temperature activity. According to the characterization, the presence of Ce increased the total acid amount and the ratio of Cu+/Cu2+ on the surface. Besides, the adsorption and oxidation of NO were also increased. While the introduction of Mn increased the amount of CuO on the surface of Cu-SAPO-34 and decreased the total acid amount accordingly. The oxidation of NH3 at high temperature was promoted with the presence of Mn resulting in the decreasing NH3 concentration involved in the NH3-SCR reaction.

关 键 词：Cu-SAPO-34催化剂 NH3-SCR NOX脱除 稀土金属 过渡金属 

分 类 号：TQ426.8[化学工程]