在Li/Sm2O3上进行甲烷氧化偶联制C2烃的研究 Ⅰ.Sm2O3添加碱金属和碱土金属化合物的性能考察

Investigation of the oxidative coupling of methane over Li/Sm2O3 catalysts Ⅰ. Performance test of Sm2O3 with the addition of alkali metal and alkali-earth metal compounds

在常压下,采用固定床反应器,考察了添加各种碱金属和碱土金属化合物的Sm_2O_3催化剂的催化性能。结果发现,LiCl和LiNO_3的加入能显著提高催化剂活性和C_2烃生成选择性。还研究了Li的添加量、焙烧温度对催化剂性能的影响。在Sm_2O_3中添加LiNO_3,由于形成了SmLiO_2复合氧化物,不仅改善了催化性能,而且很好地解决了Li易流失的问题,使催化剂稳定性增加,能连续反应25h而保持活性和C_2烃选择性不变。此外,还对820℃下焙烧的Li含量5%的LiNO_3/Sm_2O_3催化剂进行了使用工艺条件的考察,得到了LiNO_3/Sm_2O_3催化剂的最佳使用工艺条件。

At atmospheric pressure,samarium oxide and alkali or alkali-earth promoted oxide catalysts have been tested for the oxidative coupling of methane using a fixed bed reactor. The results indicate that the addition of LiCl or LiNO_3 effectively enhances the catalysis activity and selectively to C_2. The effects of Li content and calcination temperature on the catalysis activity have been investigated. As the formation of SmLiO_2, the loss of lithium of LiNO_3/Sm_2O_3 catalyst should be limited. The coupling reaction of methane over this catalyst for 25 hours has shown that the activity and C_2 selectivity remain constant. In addition, the operation process conditions of LiNO_3/Sm_2O_3 (5% Li) catalyst calcined at 820℃ have been investigated.