Ce-P复合改性HZSM-5分子筛的乙醇制乙烯性能研究  

Study on catalytic performance of HZSM-5 zeolite modified by cerium and phosphor for ethanol dehydration to ethylene

作　　者：韩伟[1] 何霖[1] 谭亚南[1] 

机构地区：[1]西南化工研究设计院有限公司国家碳一化学工程技术研究中心工业排放气综合利用国家重点实验室,四川成都610225

出　　处：《天然气化工—C1化学与化工》2013年第6期12-15,共4页Natural Gas Chemical Industry

摘　　要：合成了HZSM-5分子筛,在此基础上制备了不同含量Ce-P复合改性HZSM-5分子筛样品,并采用X射线衍射、N2低温物理吸附和吡啶吸附-红外光谱等手段对分子筛进行了表征。在常压、乙醇质量空速1.5h-1、温度为280℃的反应条件下,在固定床反应器上考察了改性分子筛乙醇脱水制乙烯的催化性能。结果表明,少量的Ce-P复合改性的HZSM-5的MFI结构没有改变,但Ce的加入,使其表面酸含量减少,尤其是强酸为主的B酸中心减少更为明显,使得表面L酸中心与B酸中心的比值(L/B)增高,从而提高了催化剂的活性和稳定性。3%Ce-1%P/HZSM-5分子筛表现出最佳的活性和稳定性,其乙醇转化率和乙烯选择性可长时间维持在99%以上。HZSM-5 zeolite was synthesized and then modified by different contents of Ce and P. The samples were characterized by XRD, N2 adsorption and pyridine-IR, and their catalytic perfolanances for ethanol dehydration to ethylene were evaluated in a fixed-bed reactor at atmospheric pressure, 280℃ and a ethanol mass hourly space velocity of 1.5 h-＇. The results showed that doping a small quantity of Ce and P wouldn＇t destroy the MFI structure of HZSM-5, but the addition of Ce could decrease the amount of acidic sites on the surfaces of the modified HZSM-5 zeolites, and the decrease of B acid sites was more obvious than L acid sites, which resuhed in increasing the ratio of L acid sites to B acid sites and enhancing the activity and stability of the catalysts. The 3%Ce-l%P/HZSM-5 showed the best activity and stability, and over it both of the ethanol conversion toni ethylene selectivity could be maintained at above 99% a long time.

关 键 词：HZSM-5 分子筛 复合改性 乙醇脱水 乙烯 

分 类 号：TQ426[化学工程]