铋取代对LaMnO_3催化剂的结构和催化碳烟燃烧性能的影响  

Effect of Bi Doping on the Structure and Catalytic Activity of LaMnO_3 Catalyst for Soot Combustion

作　　者：吴少华[1] 宋崇林[1] 宾峰[1] 吕刚[1] 宋金瓯[1] 李晓东[1] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《燃烧科学与技术》2014年第2期152-157,共6页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(51206119);天津市应用基础及前沿技术研究计划资助项目(13JCZDJC35800)

摘　　要：采用柠檬酸溶胶法合成了一系列LaMn1-xBixO3(x为0,0.1,0.2,0.3,0.4)钙钛矿型催化剂,通过X射线衍射(XRD)、比表面积测定(BET)、傅里叶红外光谱(FT-IR)、程序升温还原(H2-TPR)和程序升温脱附(O2-TPD)手段对催化剂的物理化学特性进行了表征.采用热重分析法(TG/DTA)研究了铋(Bi)金属的取代对催化剂催化去除碳烟活性的影响.研究结果表明,Bi取代导致催化剂样品中Bi0.775,La0.225,O1.5氧化物的形成,并随着Bi取代量的提高该氧化物的量逐渐增多.相对于LaMnO3,金属Bi取代提高了催化剂的比表面积、表面吸附氧含量(α-O2)以及低温氧化还原能力,因此催化剂使碳烟燃烧的催化活性得到了显著的提高.该系列样品中,LaMn0.7,Bi0.3,O3样品表现出最高的催化活性,碳烟燃烧速率峰值温度(Tm)仅为394,℃.A series ofLaMn1-xBixO3 （x = 0, 0.1, 0.2, 0.3, 0.4）perovskite catalysts were prepared by the citric acid complex method. The structures and physico-chemical properties of those catalysts were characterized using X-ray diffraction（XRD）, nitrogen adsorption, Fourier transform infrared spectra（FT-IR）, H2-temperature-programmed reduction （H2-TPR） and O2-tempreature-programmed desorption （O2-TPD）. The catalytic activity for soot combustion was evaluated using a TG/DTA analyzer. The results show that the partial amount of Bi0.775 La0.225 OI.5 was formed due to bismuth substitution. Furthermore, compared with LaMnO3, Bi substitution leads to the increase of BET specific surface area, the amount of surface adsorbed oxygen （α-O2）and the redox properties of catalysts, resulting in a higher activity for soot combustion. Among those catalysts tested, LaMn0.7 Bi0.3 O3 exhibits the highest catalytic activity, with the maximum soot combustion rate temperature （Tm） of 394 ℃.

关 键 词：钙钛矿 碳烟 催化活性 碳烟燃烧速率峰值温度 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]