OMS－2负载Ag催化剂的制备及催化氧化性能研究  

Ag-doped Manganese Oxide Octahedral Molecular Sieves:Preparation and Catalytic CO Oxidation

作　　者：路恒 叶青[1] 余畅[1] 向欣[1] 杨海琳[1] 王道[1] 

机构地区：[1]北京工业大学区域大气复合拷染防治北京市重点实验室,北京100124

出　　处：《环境科学与技术》2014年第9期27-31,共5页Environmental Science & Technology

基　　金：国家自然科学基金项目(21277008,20777005);北京市教委科技发展计划面上项目(KM2013100050010)

摘　　要：以KMnO4和MnSO4为基底采用回流法合成了氧化锰八面体分子筛(OMS-2)。以OMS-2为载体采用前掺杂法和浸渍法制备了不同Ag含量的负载型OMS-2催化剂,对所制催化剂进行了结构和织构表征。并研究了不同制备方法和Ag负载量对Ag/OMS-2催化氧化CO性能的影响。结果表明,OMS-2为典型的cryptomelane一维隧道结构,适量掺杂Ag使OMS-2载体分子筛的有序性得到改善。负载型Ag/OMS-2的催化活性均明显优于OMS-2载体,且前掺杂法催化活性优于浸渍法。这与Ag/OMS-2-PI催化剂中Ag颗粒大小及OMS-2载体与Ag之间存在强相互作用有关。Ag负载量明显影响Ag/OMS-2-PI催化剂的催化活性,3Ag/OMS-2-PI催化剂(Ag=3.0 wt%)催化活性最高,这是由于适当Ag负载量,Ag颗粒较小,与载体OMS-2的相互作用较强,能较好地活化OMS-2晶格氧,同时Ag的引入使OMS-2对CO的吸附性能及晶格氧的扩散能力得到显著增强,提高了催化剂对CO的氧化催化能力。A series of Ag-doped manganese oxide octahedral molecular sieves （OMS-2）, used as a sort of catalyst for CO oxidation, were synthesized by pre-incorporation （PI） and conventional wet impregnation （IM） methods on a laboratory scale, and then the investigation was carried out in respect to characterization of the structure of catalysts by X-ray diffraction and N2 adsorption/desorption, as well as the influences of different preparation methods and Ag loading amounts on the catalytic activity in CO oxidation. The study found that the catalyst OMS-2, of a typical one-dimensional channel cryptomelane-type structure, when being loaded with adequate amount of Ag could obviously increase the specific surface area, so having much higher catalytic activity in CO oxidation than before, in addition, pre-incorporation （PI） was proven better than wet impregnation （IM）. These improvements of Ag/OMS-2 were most likely owing to the character of Ag that was able to significantly enhance the CO adsorption properties and lattice of OMS-2 and oxygen diffusion capacity, thus upgrading the catalytic ability for CO oxidation.

关 键 词：氧化锰八面体分子筛 负载催化剂 银 一氧化碳 催化氧化 

分 类 号：X131.1[环境科学与工程—环境科学]