To develop more efficient catalysts that can be operated at low temperature region for oxidative of methane (OCM), a series of Ln₂Ce₂O₇ compounds with different A sites (Ln = La, Pr, Sm and Y) have been prepared. It is revealed by XRD and Raman techniques that a defective cubic fluorite phase has been formed in all the catalysts. As a consequence, all the Ln₂Ce₂O₇ catalysts possess much stronger surface basicity and more abundant electrophilic oxygen species in comparison with individual CeO₂, which is beneficial to OCM reaction. It is believed that the concerted interaction between surface intermediate basic sites and selective electrophilic oxygen species is the predominant reason controlling the reaction performance of the catalysts. Furthermore, Ln₂Ce₂O₇ catalysts own more abundant mesopores and higher surface areas than pure CeO₂, which could also be favorable for the contacting of the reactants with the active sites. Due to the optimal synergistic interaction of these factors, La₂Ce₂O₇ exhibits the best performance among all the catalysts, on which the highest C₂ yield of 16.6% is achieved at 750 °C. In comparison with Mn/Na₂WO₄/SiO₂, the most promising catalyst at present, La₂Ce₂O₇ display much improved reaction performance at low temperature region (<750 °C).

为了开发可在低温区域操作以氧化甲烷（OCM）的更有效的催化剂，已制备了一系列具有不同A位（Ln = La，Pr，Sm和Y）的Ln ₂ Ce ₂ O ₇化合物。通过XRD和拉曼技术揭示，在所有催化剂中均已形成有缺陷的立方萤石相。结果，与单独的CeO ₂相比，所有的Ln ₂ Ce ₂ O ₇催化剂都具有更强的表面碱性和更丰富的亲电子氧物种。，这对于OCM反应是有益的。据信，表面中间碱性位点与选择性亲电子氧物种之间的协调相互作用是控制催化剂反应性能的主要原因。此外，与纯CeO ₂相比，Ln ₂ Ce ₂ O ₇催化剂具有更丰富的中孔和更大的表面积，这也可能有利于反应物与活性位点的接触。由于这些因素的最佳协同作用，La ₂ Ce ₂ O ₇在所有催化剂中表现出最佳性能，其中最高的C ₂在750°C下达到16.6％的产率。与目前最有希望的催化剂Mn / Na ₂ WO ₄ / SiO _2相比，La ₂ Ce ₂ O ₇在低温区域（<750°C）显示出大大改善的反应性能。