稀土修饰ZSM-5对氯代甲烷制备低碳烯烃的催化性能  

Catalytic Performance of Rare Earth Modified ZSM-5 in Chloromethane Conversion to Lower Olefins

作　　者：陈艳云[1] 费兆阳[1,2] 陈献[1] 汤吉海[1] 崔咪芬[1] 乔旭[1,2] 

机构地区：[1]南京工业大学化学化工学院,江苏南京210009 [2]南京工业大学材料化学工程国家重点实验室,江苏南京210009

出　　处：《石油学报（石油加工）》2016年第1期28-34,共7页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家科技支撑计划项目(2011BAE18B01);国家自然科学基金项目(21306089)资助

摘　　要：以稀土硝酸盐为前躯体,采用等体积浸渍法制备了一系列稀土修饰ZSM-5催化剂(RE/ZSM-5);利用XRD、N2吸附-脱附、SEM、NH3-TPD等手段表征了所制备RE/ZSM-5的物理化学性质,并考察了其对氯甲烷制低碳烯烃(MeXTO)反应的催化性能。结果表明,稀土修饰可以调节ZSM-5的酸性,降低催化剂的酸量和酸强度,从而提高催化剂催化MeXTO的稳定性和产物中低碳烯烃选择性。在一系列RE/ZSM-5中,Ce/ZSM-5在MeXTO反应中表现出较高的催化活性,得到较高低碳烯烃选择性,同时具有相对较长的使用寿命。在450℃、质量空速0.45h-1条件下,2Ce/ZSM-5催化MeXTO的氯甲烷转化率高达97.6%,总的低碳烯烃选择性达77.6%;反应52h后,低碳烯烃收率仍维持在43%。A series of rare earth modified ZSM-5 catalysts （RE/ZSM-5） were prepared by impregnation method with rare earth nitrates as precursors. The physiochemical properties of the prepared RE/ZSM-5 catalysts were characterized by XRD, N2 adsorption-desorption, SEM and NH3-TPD, and their catalytic performances for chloromethane to lower olefins （MeXTO） were systematically investigated. The results showed that rare earth modification could reduce the acid amount and acid strength of ZSM-5, which was in favor of increasing selectivity to lower olefins and catalyst lifetime. Among RE/ZSM-5, Ce/ZSM-5 exhibited the longest catalytic life in MeXTO and highest olefins selectivity could be obtained. Under the conditions of 450℃ and 0.45 h 1, chloromethane conversion and selectivity to lower olefins were 97.6% and 77.6%, respectively. Notably, the yield of lower olefins was still as high as 43% after 52 h reaction.

关 键 词：氯甲烷 低碳烯烃 RE/ZSM-5 酸量 酸强度 

分 类 号：TE646[石油与天然气工程—油气加工工程]