【摘要】 以PEG 400为分散剂,采用一步柠檬酸络合法制备了LaXCoO3(X=Mg,Ca,Sr,Ce;La:X=3:2)复合催化剂.采用X射线衍射、红外光谱、扫描电镜、X射线光电子能谱、N2吸附-脱附和H2程序升温还原等技术对复合催化剂进行了表征,考察了不同元素A位取代对LaCoO3钙钛矿结构的影响,进而研究了其对乙醇水蒸气重整制氢的催化性能和稳定性.结果表明,在高含量取代时,只有Ce取代的样品能够保持单一的钙钛矿晶型;Ca或Sr取代的样品产生的Co3O4分离相有利于复合催化剂活性中心钴的还原;Sr或Ce取代的样品在反应中表现出较好的活性和稳定性,Sr取代的样品活性更高.更多还原

【Abstract】 Perovskite nanocomposite catalysts LaXCoO3(X = Mg, Ca, Sr, or Ce; n(La):n(X) = 3:2) have been prepared by a citric acid‐complexing method and used for steam reforming of ethanol(SRE), lead‐ing to hydrogen generation. The samples were characterized by X‐ray diffraction, infrared spec‐troscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy, N2 adsorp‐tion‐desorption, and H2 temperature‐programmed reduction. The effects of elemental substitution in the LaCoO3 perovskite were studied, and the catalytic performance and primary stability of the hydrogen production from SRE were investigated. In the highly substituted samples, only the Ce‐doped sample was isolated as the pure perovskite phase. The presence of a Co3O4 phase in the Ca‐doped or Sr‐doped samples was beneficial for the reduction of the active Co component, while Sr‐doped or Ce‐doped samples showed good activity and stability. The sample incorporating Sr demonstrated better catalytic performance than those of other samples.更多还原