B位离子掺杂对LaSrFeMO_(6)催化剂结构及性能的影响

Effect of B-site ions doping on the structure and methane combustion activity of catalysts LaSrFeMO_(6)

以柠檬酸为络合剂,采用溶胶凝胶-酸蚀法制备了LaSrFeMO_(6)(M=Co,Cr,Mn,Cu,Ni)催化剂,利用XRD,BET,H2-TPR,TG-DSC,SEM等方法对制备的催化剂进行表征,并将制备的催化剂应用于甲烷燃烧反应,考察了B位离子掺杂对催化剂活性的影响。实验结果表明,不同B位离子掺杂对催化剂的结构有一定的影响,LaSrFeMO_(6)催化剂均具有双钙钛矿型结构,但比表面积存在较大差异,其中,LaSrFeMnO_(6)催化剂稳定的比表面积最大,为35.1 m^(2)/g,该催化剂被硝酸酸蚀效果显著,不仅形成了双钙钛矿型催化剂结构而且增加了催化剂的比表面积及反应位点,提高了催化剂的催化甲烷燃烧的能力。

LaSrFeMO_(6)(M=Co,Cr,Mn,Cu,Ni)series catalysts were prepared by sol-gel-acid etching method using citric acid as complexing agent.The title catalysts were characterized by XRD,BET,H2-TPR,TG-DSC and SEM techniques.The catalytic activities were evaluated by methane combustion.The influence of B-site ions doping on catalytic activity of LaSrFeMO_(6) was investigated.The results showed that B-site ions doping have certain influence on the structure of the catalyst.The title LaSrFeMO_(6) catalysts could form a complete perovskite crystal type.There are great differences in specific surface area.The catalyst LaSrFeMnO_(6) retains a larger specific surface area of 35.1 m^(2)/g.Acid etching had a great influence to form catalyst LaSrFeMnO_(6).It can increase the specific surface area and active site,which improves the catalytic activity for methane catalytic combustion.