助剂对Cu-Mn复合氧化物整体式催化剂催化低浓度甲烷燃烧反应性能的影响  

Effect of Promoter on the Performance of Cu-Mn Complex Oxide Monolithic Catalysts for Lean Methane Catalytic Combustion

作　　者：张佳瑾[1] 李建伟[1] 朱吉钦[1] 王越[1] 陈标华[1] 

机构地区：[1]北京化工大学化工资源有效利用国家重点实验室,北京100029

出　　处：《催化学报》2011年第8期1380-1386,共7页

基　　金：国家高技术研究发展计划(863计划;2006AA030201)~~

摘　　要：以堇青石蜂窝陶瓷(COR)为载体,采用浸渍法制备了Cu-Mn-O/Al2O3/COR,Cu-Mn-Ce-O/Al2O3/COR,Cu-Mn-Zr-O/Al2O3/COR,Cu-Mn-La-O/Al2O3/COR和Cu-Mn-Ce-Zr-O/Al2O3/COR5种Cu-Mn复合氧化物整体式催化剂,用于低浓度甲烷催化燃烧反应,并运用X射线光电子能谱,H2程序升温还原及N2吸附-脱附等方法对催化剂进行了表征,考察了助剂CeO2,ZrO2,La2O3和CeO2-ZrO2对Cu-Mn复合氧化物整体式催化剂性能的影响.结果表明,助剂的添加不仅能明显提高催化剂的比表面积、促进各活性组分的分散和表面氧浓度的增加,从而可提高催化剂表面的氧化能力,而且对催化剂的孔结构分布也起到了良好的调节作用,有利于催化剂上反应-扩散耦合行为的匹配;同时,助剂的添加较大幅度地提高了Cu-Mn-O/Al2O3/COR催化剂的活性(尤其是低温催化活性),其中以ZrO2为助剂制备的Cu-Mn-Zr-O/Al2O3/COR整体式催化剂性能最佳,在570?C和20000h-1高空速条件下,可使甲烷转化率达到90%以上,表现出良好的甲烷催化燃烧活性.Five Cu-Mn complex-oxide catalysts supported on cordierite（COR）monolithic,Cu-Mn-O/Al2O3/COR,Cu-Mn-Ce-O/Al2O3/COR,Cu-Mn-Zr-O/Al2O3/COR,Cu-Mn-La-O/Al2O3/COR,and Cu-Mn-Ce-Zr-O/Al2O3/COR,for the catalytic combustion of lean methane were prepared by wetness impregnation using cordierite as the support.The effect of promoters such as CeO2,ZrO2,La2O3,and CeO2-ZrO2,on the structure and properties of Cu-Mn-O/Al2O3 was characterized by X-ray photoelectron spectroscopy,H2 temperature-programmed reduction,and N2 adsorption-desorption.The catalytic performance of lean methane catalytic combustion over these catalysts was evaluated in a fixed-bed reactor.The results showed that with the introduction of CeO2,ZrO2,La2O3,and CeO2-ZrO2 as the promoter to Cu-Mn-O/Al2O3/COR,the specific surface area of the catalysts increases obviously,resulting in an enhancement of active component dispersion and oxygen species concentration on the catalyst surface.Therefore,the surface oxidation reactivity of the catalysts is improved.Besides,the pore structure of the catalysts is also adjusted well,which is beneficial for matching the diffusion-reaction coupling behavior on the catalyst.The activity of Cu-Mn-O/Al2O3/COR,especially the low-temperature activity remarkably increases with the promoter addition.Among the tested promoters,ZrO2 shows the best promoting effect.The methane conversion over Cu-Mn-Zr-O/Al2O3/COR monolithic catalyst is up to 90% under the conditions of 570 0C and GHSV = 20000 h-1.

关 键 词：铜锰复合氧化物 稀土金属氧化物 整体式催化剂 甲烷 催化燃烧 

分 类 号：O643.36[理学—物理化学]