Mo/HZSM-5催化乙醇脱水制乙烯  

Ethanol Dehydration to Ethylene over Mo/HZSM-5 Catalyst

作　　者：陆翠云[1] 张叶龙[1] 韩毓旺[1] 胡燚[2] 

机构地区：[1]南京工业大学理学院,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：《石油化工》2011年第12期1281-1286,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：以HZSM-5分子筛为载体、采用等体积浸渍法制备了不同Mo负载量的Mo/HZSM-5催化剂,采用BET,XRD,NH3-TPD,H2-TPR,TG等方法考察了Mo负载量对催化剂的结构、表面酸性和还原性的影响,并与催化剂的乙醇脱水反应活性和稳定性进行了关联。实验结果表明,随Mo负载量的增加,催化剂的比表面积和孔体积逐渐减小、总酸量减少、中强酸量逐渐增加。Mo负载量为5.0%(w)的Mo/HZSM-5催化剂(MHZ-5.0)的中强酸量较多,催化活性最佳;Mo负载量为10.0%(w)的Mo/HZSM-5催化剂中部分Mo抽提了骨架铝,破坏了分子筛骨架结构,催化活性下降。在反应温度250℃、重时空速3.0 h-1、0.1 MPa、MHZ-5.0催化剂6 g、50%(w)乙醇溶液进料的条件下反应200 h后,乙醇转化率和乙烯选择性仍维持在97%以上,远高于HZSM-5分子筛原粉,说明Mo的添加不仅提高了催化剂的活性还有效延长了催化剂的使用寿命。Mo/HZSM-5 catalysts were prepared by impregnation using HZSM-5 molecular sieves as the support.The effects of Mo loading on the structure,acidity and reducibility of the catalysts were investigated by means of BET,XRD,NH3-TPD,H2-TPR and TG.The catalytic activity of the catalysts in dehydration of ethanol to ethylene was studied.It was found that with the increase of Mo loading,the specific surface area,pore volume and total acid amount in the catalysts decreased while the acid amount with medium strength increased.5.0%（w）Mo/HZSM-5 with much amount of the medium strong acid showed the best catalytic performance among the catalysts.The catalytic activity of 10.0%（w）Mo/HZSM-5 decreased because the Mo species extracted the framework aluminum in the catalyst.Besides,the stability of 5.0%（w）Mo/HZSM-5 catalyst in 50%（w） ethanol solution was evaluated.Under the reaction conditions： 250 ℃,WHSV 3.0 h-1,0.1 MPa and catalyst dosage 6 g,both the ethanol conversion and the ethylene selectivity reached more than 97% after reaction for 200 h,which indicated that Mo modification could improve the activity and stability of the catalysts.

关 键 词：乙醇脱水 乙烯 MO/HZSM-5催化剂 表面酸性 

分 类 号：TQ426[化学工程]