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

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 N2adsorption/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.