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为了研制用于从天然气制取乙烯的，具有良好的催化活性、选择性和稳定性的催化剂，用溶胶－凝胶法合成了系列稀上－锡复合氧化物Ｌａ２－ｘＳｍｘＳｎ２Ｏ７（ｘ＝０．０，０．５，１．０，１．５，２．０）．用ｘＲＤ对其结构研究表明：Ｌａ２－ｘＳｉｎｘＳｎ２Ｏ７，系列稀土－锡复合氧化物均具有烧绿石型结构，属立方晶系，空间群为Ｆ３ｄｍ．同时发现其晶胞参数ａｐｙｒ随Ｓｍ掺入量增加而近乎线性减小．并在脉冲激反应器上，对其催化活性进行评价．结果表明：Ｓｍ２Ｓｎ２Ｏ７复合氧化物对甲烷氧化偶联反应具有良好的催化活性，在ＣＨ４／Ｏ２＝４，温度在８００℃～９００℃，Ｘ＝２．０时，Ｃ２选择性为３８．１％，产率为９．２％，其中Ｃ２＝的选择性为２７．９％，产率为６．４％．同时发现晶格缺陷的形成有利于催化剂催化活性的提高．
In order to develop a catalyst with good catalytic activity, selectivity and stability for the production of ethylene from natural gas, a series of dilute-tin complex oxides La2-xSmxSn2O7 (x = 0.0 , 0.5, 1.0, 1.5, 2.0). The results of XRD showed that La2-xSinxSn2O7 and series of rare earth-tin composite oxides all have the pyrochlore structure, belonging to the cubic system with space group F3dm. At the same time, it was found that the unit cell parameter apyr decreased nearly linearly with the increase of Sm content. And in the pulse reactor, its catalytic activity was evaluated. The results showed that the selectivity of Sm2Sn2O7 composite oxide to methane oxidative coupling reaction was 38.1% at CH4 / O2 = 4, temperature of 800 ℃ ~ 900 ℃ and X = 2.0. The yield was 9.2% with a C2 = selectivity of 27.9% and a yield of 6.4%. It is also found that the formation of lattice defects is conducive to the improvement of catalytic activity of the catalyst.