摘要
采用柠檬酸法制备了Ce-Zr-La-Co复合氧化物催化剂和LaCoO3/Ce0.6Zr0.4O2负载型催化剂,并用热重法测试了2种催化剂对碳烟的催化活性,催化剂LaCoO3/Ce0.6Zr0.4O2显示了更高的活性,碳烟的起燃温度是542℃,低于Ce-Zr-La-Co复合氧化物催化剂的552℃,比纯碳烟的起燃温度低97℃.采用程序升温还原法(Hydrogen Temperature-programmed Reduction,H2-TPR)、N2吸附BET、X-射线衍射仪(X-ray Diffraction,XRD)、傅立叶红外仪(Fourier Transform Infrared Spectroscopy,FTIR)和X-射线光电子能谱仪(X-ray Photoelectron Spectroscopy,XPS)等技术对催化剂进行了表征.结果表明,XRD显示负载型氧化物LaCoO3/Ce0.6 Zr0.4 O2形成了完好的钙钛矿结构相,而Ce-Zr-La-Co复合氧化物则形成了铈锆固溶体为主以及少量的钙钛矿和Co3O4氧化物相;XPS结果显示LaCoO3/Ce0.6Zr0.4O2催化剂表面弱吸附氧Oˉ的含量高达质量分数34.9%,而复合体氧化物的含量仅为质量分数16.1%,催化剂的活性可能与表面弱吸附氧有关.
Ceria-zirconia solid solution-supported LaCoO3 and Ce-Zr-La-Co compound oxide were prepared using citric method.The catalytic activity of catalysts on soot was determined by thermogravimetry（TG）.Ignition temperature of LaCoO3/Ce0.6Zr0.4O2 on soot is lower than 552 ℃ of Ce-Zr-La-Co compound oxide,i.e.542 ℃ vs 552 ℃.However,which is 97 ℃ lower than that of pure soot.All the properties on catalysts as prepared were investigated by techniques such as Temperature-programmed Reduction（H2-TPR）,BET surface area,X-ray Diffraction（XRD）,Fourier Transform Infrared Spectroscopy（FTIR）and X-Ray Photoelectron Spectroscopy（XPS）.XRD results indicated good perovskite phase was formed on LaCoO3/Ce0.6Zr0.4O2;besides main ceria-zirconia solid solution phase,a small amount perovskite phase and Co3O4 phase existed in Ce-Zr-La-Co compound oxide.XPS results reflected the weakly-adsorbed Oˉ anions content on LaCoO3/Ce0.6Zr0.4O2 was 34.9%,higher than 16.1% of Ce-Zr-La-Co compound oxide.Catalytic performance was related to the weakly adsorbed Oˉ anions.
出处
《仲恺农业工程学院学报》
CAS
2010年第4期1-6,共6页
Journal of Zhongkai University of Agriculture and Engineering
基金
仲恺农业工程学院博士科研启动基金(G2360275)资助项目
