钴掺杂Mn氧化物催化剂对NH_(3)-SCR活性及抗SO_(2)/H_(2)O中毒特性的研究

Investigation of Co-doped Mn oxide catalyst for NH_(3)-SCR activity and SO_(2)/H_(2)O resistance

采用共沉淀法制备了一系列不同物质的量比的钴掺杂锰氧化物催化剂,并对其进行了系统表征。讨论了钴掺杂锰的氧化物催化剂的NH_(3)-SCR催化活性和抗水抗硫性能。结果表明,锰钴物质的量比为16∶1的Co(1)-MnO_(x)催化剂的催化性能最好,在100−275℃时实现了大于90%的NO_(x)转化率,并且耐水性和耐硫性较好。Co(1)-MnO_(x)催化剂呈现出球状结构,拥有相对较大的表面积。钴掺杂锰增加了催化剂表面的高价金属离子和化学吸附氧含量。Co(1)-MnO_(x)催化剂具有丰富的活性物种和酸性位点,降低了催化剂的表观活化能。

A series of Co-doped Mn oxide catalysts with different Co/Mn molar ratios were prepared by co-precipitation method,which was systematically characterized by XRD,SEM,H_(2)-TPR and NH_(3)-TPD etc.Co-doped Mn oxide catalysts are evaluated for NH_(3)-SCR activity and resistance to SO_(2) and/or H_(2)O,and the Co(1)-MnO_(x) catalyst with Mn/Co molar ratio of 1∶1 performs the best catalytic performance,which achieved higher than 90%NO_(x) conversion in the temperature range of 100−275℃ and possessed better SO_(2) and H_(2)O resistance.The Co(1)-MnO_(x) catalyst presented a sphere-like structure possessing a relatively large surface area.Doping of cobalt greatly improved the high-valent metal ions and chemisorbed oxygen content of Co(1)-MnO_(x) catalyst surface,and the catalyst possessed abundant active species and acid sites and apparent activation energy of the catalyst was reduced,which makes Co(1)-MnO_(x) a highly effective NH_(3)-SCR catalyst.