Abstract The synthesis, structural, spectroscopic and morphological characterization; as well as the evaluation of the catalytic properties, of a family of oxides La2MMnO6, with M = Co, Ni and Cu are presented in this work. The materials were obtained by solid state reaction and through citrate route. The structure was determined by X-ray diffraction and a correlation was found between the crystal cell parameters and the M(II) cation sizes, as a consequence of MO6 and MnO6 octahedral ordering. According to infrared spectroscospic characterization of the materials prepared by citrate route, a diminution of the M4+-O bond strength was observed, according with M(II) sizes, in the sequence: Cu > Ni > Co. More labile O species should be present in La2CoMnO6-CIT. The electron microscopy morphology of this oxide confirmed the presence of agglomerated tiny particles. The presence of nanometic crystallites was confirmed by transmission electron microscopy. The catalytic tests, using propane as reaction test, were carried out in a fixed bed micro reactor, coupled with an “on line” chromatograph. The materials obtained by citrate route, despite M(II) cations, are better suited for propane combustion and the catalyst La2CoMnO6 is the most active of the investigated series with T90 ∼ 500 °C.

中文翻译：

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双钙钛矿La 2 MMnO 6 作为丙烷燃烧催化剂

摘要 合成、结构、光谱和形态表征；以及对一系列氧化物 La2MMnO6 的催化性能的评估，其中 M = Co、Ni 和 Cu 在这项工作中提出。该材料通过固态反应和柠檬酸盐途径获得。该结构由 X 射线衍射确定，并且发现晶胞参数与 M(II) 阳离子尺寸之间存在相关性，这是 MO6 和 MnO6 八面体排序的结果。根据柠檬酸盐路线制备的材料的红外光谱表征，观察到 M4+-O 键强度降低，根据 M(II) 尺寸，顺序为：Cu > Ni > Co。应该存在更多不稳定的 O 物种在 La2CoMnO6-CIT 中。这种氧化物的电子显微镜形态证实存在附聚的微小颗粒。通过透射电子显微镜证实了纳米微晶的存在。催化试验以丙烷为反应试验，在固定床微型反应器中进行，并配以“在线”色谱仪。通过柠檬酸盐途径获得的材料，尽管有 M(II) 阳离子，但更适合丙烷燃烧，催化剂 La2CoMnO6 是所研究系列中活性最高的，T90 ～ 500 °C。