【摘要】 研究了甲烷在ＬＣ和ＳＬＣ催化剂体系上氧化偶联反应过程的热效应现象和反应气中添加ＣＯ２对催化剂反应行为的影响．在不使用稀释气的情况下，当反应温度由８７３升至９２３Ｋ时，反应活性存在一个突变点．这主要是由ＣＨ４燃烧反应放出大量热使催化剂床层的局部温度很高，形成一个局部过热区，因此引发甲烷氧化偶联．此即所谓热点温度效应，它严重影响催化剂活性评价结果的可靠性和重复性．在反应气中添加ＣＯ２对ＬＣ几乎无影响；由于ＳＬＣ中各组分与ＣＯ２作用生成碳酸盐，使催化剂表面氧浓度显著减少，导致催化剂的反应活性大大降低和严重失活．更多还原

【Abstract】 he phenomenon of hot spot temperature and the effect of CO2 on the catalytic performance were studied for oxidative coupling of methane over La2()3/CaO(LC) and SrO-La2O3/CaO (SLC) catalysts. There was an abrupt change of the reactivity of SLC when the reaction temperature increased fron 873 to 923 K if no inert gas was used in the feed.This was mainly caused by the total oxidation of methane, releasing combustion heat and therefore, forming a local over-heated spot in the catalyst bed. Then the reaction of oxidative coupling of methane was initiated.It was found that the addition of CO2 to the feed caused a severe effect on the catalytic performance of SLC, especially if the SrO content was higher, while no efffect could be detected for I.C catalyst.The deactivation was mainly attributed to the formation of SrCO,,which was difficult to dissociate under the reaction conditions.更多还原