合成方法对γ-Al_2O_3催化剂乙醇脱水性能的影响  

Effect of Preparation Method for γ-Al_2O_3 Catalyst on Dehydration of Ethanol

作　　者：李慧[1] 胡燚[1] 苏国东[1] 成源海[1] 黄和[1] 

机构地区：[1]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：《石油化工》2009年第4期373-378,共6页Petrochemical Technology

基　　金：国家高技术研究发展计划项目(2006AA020101);国家科技支撑计划重点资助项目(2006BAE02B04)

摘　　要：分别采用溶胶-凝胶法和沉淀法合成了γ-Al2O3催化剂,采用X射线衍射、热重分析、N2吸附-脱附、NH3程序升温脱附等方法对制备的γ-Al2O3催化剂进行了表征,考察了它们对乙醇脱水制乙烯反应的催化性能,并分析了γ-Al2O3催化剂表面羟基密度和酸强度对催化性能的影响。研究结果表明,溶胶-凝胶法制得的γ-Al2O3催化剂具有较强的表面酸性,能更有效地催化乙醇脱水制乙烯反应。考察了反应温度、液态空速及乙醇质量分数对乙醇脱水制乙烯反应的影响,在反应温度350℃、液态空速0.6h-1、乙醇质量分数92.4%的条件下,采用溶胶-凝胶法制得的γ-Al2O3催化剂,乙醇转化率和乙烯选择性分别达到99.3%和97.7%。γ-Al2O3 catalysts for dehydration of ethanol to ethylene were prepared by both sol-gel and precipitation methods, and characterized by means of XRD, TG, N2 adsorption-desorption and NH3-TPD. The activities of ethanol dehydration on the two γ-Al2O3 catalysts were observed. Effects of -OH group density and surface acidity of the catalysts were analyzed. The catalyst prepared by solgel method was higher in surface acidity and was more active in the dehydration. Under optimal conditions：350℃, LHSV of ethanol 0.6 h^-1 and ethanol mass fraction in feed 92.4%, ethanol conversion and selectivity to ethylene on γ-Al2O3 catalyst prepared by sol-gel method could reach 99.3% and 97.7%, respectively.

关 键 词：Γ-氧化铝 催化剂 溶胶-凝胶法 沉淀法 乙醇脱水 乙烯 

分 类 号：TQ032.4[化学工程]