有机燃料对合成大比表面积La_(0.8)Sr_(0.2)CoO_3性能的影响

Effect of organic fuels on properties of La_(0.8)Sr_(0.2)CoO_3 catalysts with large surface area

采用溶液燃烧合成法(solution com bustion synthesis,简称SCS)制备了La0.8Sr0.2CoO3钙钛矿复合氧化物,考察了丙氨酸、氨基乙酸和丙三醇等有机燃料对催化剂结构和CH4催化燃烧活性的影响,并运用XRD、FI-TR、BET、TPR等技术进行了表征。结果表明,不同有机燃料所制La0.8Sr0.2CoO3复合氧化物均具有较大比表面积,有机燃料对催化剂的结构和性能有较大的影响,其中以丙氨酸有机燃料制备的复合氧化物活性最好,其T50和T100分别为470℃和550℃。该法所制La0.8Sr0.2CoO3复合氧化物的平均晶粒度较小,比表面积和晶格畸变率较大,表面和氧空穴处的化学吸附氧较易移动,表观活化能较低。

The perovskite La0.8Sr0.2CoO3 mixed oxides were prepared by the solution combustion synthesis and used successfully for CH4combustion. The prepared samples were characterized by XRD, IR, BET and TPR. The effects of organic fuels on the structure and the catalytic activities of La0.8Sr0.2CoO3mixed oxides were studied. The results indicated that all La0.8Sr0.2CoO3mixed oxides had large surface area, whose structure and catalytic activities were related to the corresponding organic fuels. The catalytic activity of La0.8Sr0.2CoO3 catalyst prepared by alanine solution combustion synthesis was the best among all samples, whose T50 and T100 were 470℃ and 550℃ ,respectively, which could be explained in terms of the smaller of average crystal size, the higher of specific surface and lattice distortion, the lower of activation energy and easier mobile of chemical-adsorped oxygen in the surface and vacancy.