分子筛催化苯和低浓度Cl_2混合气制氯化苯的性能  

Catalytic performance of benzene to chlorobenzene with low concentration chlorine in mixed gas over zeolite catalysts

作　　者：喻其成 崔咪芬[1] 乔旭[1,2] 陈献[1] 汤吉海[1] 费兆阳[1,2] YU Qicheng;CUI Mifen;QIAO Xu;CHEN Xian;TANG Jihai;FEI Zhaoyang(College of Chemical Engineering,Nanjing Tech University,Nanjing 210009,China;State Key Laboratory of Materials Oriented Chemical Engineering,Nanjing Tech University,Nanjing 210009,China)

机构地区：[1]南京工业大学化工学院,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：《南京工业大学学报（自然科学版）》2018年第1期34-39,共6页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：江苏省产学研前瞻性联合研究项目(BY2015005-02)

摘　　要：以HCl为Cl源经催化氧化,制备不同组成的HCl和Cl_2等的混合气体。考察在分子筛催化下混合气体中Cl_2浓度对苯氯化反应速率和Cl_2利用率的影响。比较不同氢型分子筛HY、HZSM-5、Hβ和稀土改性Y型分子筛(REY)的孔道结构、酸性对苯氯化反应的催化性能。通过BET、NH3程序升温脱附(NH3-TPD)、吡啶吸附傅里叶红外光谱(Py-FT-IR)等技术对催化剂进行表征。结果表明:混合气体中Cl_2浓度对苯氯化反应影响很小,分子筛的孔道结构及其酸种类是影响苯转化率的关键因素;Hβ分子筛由于其具有三维特殊孔道、合适的酸强度和较多的Lewis酸(L酸)酸量,其催化活性明显优于HY、HZSM-5分子筛;REY分子筛含L酸最多,催化活性最高。当Cl_2质量分数为15%,反应3 h时,在REY分子筛催化下,氯化苯的平均生成速率为8.4 g/(g·h)。Low concentration chlorine and hydrogen chloride were prepared through the catalytic oxidation of hydrogen chloride and oxygen.Then,the effects of chlorine concentration on the reaction rate and utilization ratio of chlorine for benzene chlorination to chlorobenzene over zeolite catalysts were investigated.The catalytic performance of chlorination of benzene among various H-type zeolites,such as HY,HZSM-5,and Hβ,and a rare earth metal modified Y-type zeolite(REY)with different pore structures and acidity were compared.These zeolite catalysts were characterized by BET,NH3temperature programmed desorption(NH3-TPD)and pyridine adsorption Fourier transform infrared(Py-FT-IR).Results indicated that the chlorine concentration had little effects on the rate of benzene chlorination and utilization ratio of chlorine.The pore structure and acid type of zeolite catalysts were the key factors affecting the benzene conversion.Hβzeolite,due to its three dimensional special pores,appropriate acid strength and more Lewis acid(L acid)sites,had better catalytic activity than HY and HZSM-5.Among the above mentioned four zeolite catalysts,REY zeolite was the most efficient catalyst,which had enough L acid sites.When the chlorine mass concentration was15%and the reaction time was3h,the average formation rate of chlorobenzene was8.4g/(g·h)over REY zeolite.

关 键 词：低浓度Cl2 苯氯化 分子筛 LEWIS酸 

分 类 号：TQ032.4[化学工程]