Ho改性OMS-2催化CO选择性还原NO的研究  

Study on Ho-modified OMS-2 Catalysts for Selective Catalytic Reduction of NO by CO

作　　者：罗冰冰 黄嘉玮 汪朱峰 苏亚欣[1] LUO Bing-bing;HUANG Jia-wei;WANG Zhu-feng;SU Ya-xin(School of Environmental Science and Engineering,Donghua University,Shanghai 201600,China)

机构地区：[1]东华大学环境科学与工程学院,上海201600

出　　处：《分子催化》2023年第3期264-273,I0002,共11页Journal of Molecular Catalysis(China)

基　　金：国家自然科学基金项目(52276103)。

摘　　要：采用水热法一步合成了Ho改性的氧化锰八面体分子筛催化剂(Hox-OMS-2),并对其CO选择性催化还原NO(CO-SCR)性能进行了研究.研究结果表明,当Ho/Mn摩尔比为0.05时,Ho_(0.05)-OMS-2催化剂在225℃时可实现98.3%的NO转化率和N_(2)选择性.Ho的掺杂过量时会导致催化剂团聚.此外,在0.02%SO_(2)存在时,Ho_(0.05)-OMS-2催化剂在200~250℃时仍能保持80%以上的NO转化率,并具有较好的抗硫性能.通过XRD、BET、XPS、H_(2)-TPR和NH_(3)-TPD对催化剂进行表征,探究Ho物种的掺杂对OMS-2催化剂的物理化学性质的影响.结果表明,Ho_(x)-OMS-2催化剂低温活性的增强可归因于晶格膨胀、较低的结晶度、高比表面积、较高的Mn^(4+)含量、更多的表面氧空位和Brønsted酸性位的生成等.One-step hydrothermal synthesis method was used to prepare the Ho-doped Manganese oxide octahedral molecular sieves catalyst(Hox-OMS-2)and the reactivity for selective catalytic reduction of NO with CO(CO-SCR)was examined.The outcomes demonstrated that the Ho_(0.05)-OMS-2 catalyst displayed very attractive CO-SCR activity at 225℃when the Ho/Mn molar ratio was 0.05,e.g.,98.3%NO conversion and N_(2) selectivity.Furthermore,even in the presence of 0.02%SO_(2),the Ho_(0.05)-OMS-2 catalyst can retain more than 80%NO conversion at 200~250℃,and the catalyst has good sulfur resistance.SEM,XRD,BET,XPS,H_(2)-TPR,NH_(3)-TPD,and other techniques were used to characterize the catalysts and analyze how the presence of Ho species in Ho_(x)-OMS-2 affected their physicochemical properties and reactivity.The outcomes show that the lattice expansion,decreased crystallinity,high specific surface area,increased Mn^(4+)concentration,enhanced surface oxygen vacancies,and Brønsted acidic bit can all contribute to the improved low-temperature activity of Hox-OMS-2 catalysts.

关 键 词：OMS-2 Ho改性 CO-SCR 抗SO_(2) 

分 类 号：O643.32[理学—物理化学]