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采用X射线电子能谱(XPS)实验技术,对具有钙钛石结构的稀土铁复合氧化物高变催化剂进行了研究。结果表明:在La1-xCexFeO3钙钛石结构中,铈的价态为正四,镧的价态为正三,而铁为正二、正三混合价态,三价铁和二价铁的摩尔比与稀土镧铈的摩尔比具有很好的一致性;在钙钛石ABO3结构中,A位镧、铈能有效控制B位铁的价态。铁具有混合价态是La1-xCexFeO3催化剂具有较高变换催化活性的主要原因。La1-xCexFeO3表面上存在α吸附氧和β晶格氧两类氧种,随铈含量的增加,表面吸附氧增加。
The X-ray photoelectron spectroscopy (XPS) experimental technique was used to study the RE catalyst with perovskite structure. The results show that the valence state of cerium is positive four, the valence state of lanthanum is three, and the iron is positive two, three mixed valence states, the molar ratio of ferric and ferrous iron is the same as that of rare earth lanthanum in La1-xCexFeO3 perovskite structure, Cerium molar ratio has a good consistency; in the ABO3 structure, A-bit lanthanum, cerium can effectively control the B-state iron valence. Iron has a mixed valence state of La1-xCexFeO3 catalyst has a higher conversion catalytic activity of the main reasons. There are two kinds of oxygen species, α-adherent oxygen and β-lattice oxygen, on the surface of La1-xCexFeO3. With the increase of cerium content, the surface adsorbed oxygen increases.