改性NiO-La_2O_3/ZSM-5催化苯与甲醇烷基化反应性能  

Catalytic Performance of NiO-La_2O_3/ZSM-5 for Benzene Alkylation with Methanol

作　　者：高科[1] 李书珍[1] 王磊[1] 叶子新 

机构地区：[1]上海应用技术学院化学与环境工程学院,上海201418

出　　处：《上海应用技术学院学报（自然科学版）》2015年第4期337-343,共7页Journal of Shanghai Institute of Technology: Natural Science

摘　　要：采用NaOH溶液对ZSM-5分子筛进行碱处理以获得介孔结构,再采用等体积浸渍法,以硝酸镍和硝酸镧溶液为浸渍液制备了NiO-La_2O_3/ZSM-5分子筛催化剂,并进行X射线荧光衍射(XRD)、扫描电子显微镜(SEM)、比表面积(BET)和氨的程序升温脱附(NH_3-TPD)等表征.将改性NiO-La_2O_3/ZSM-5在固定床反应器中催化苯与甲醇烷基化的反应,并进行工艺条件的探索.结果表明:改性NiO-La_2O_3/ZSM-5分子筛依然保持MFI结构,但产生了大量介孔结构;强酸中心强度减弱,酸量降低,有利于苯与甲醇烷基化反应转化率和选择性的提高;改性NiO-La_2O_3/ZSM-5分子筛催化苯与甲醇烷基化的最佳反应条件为温度450°C,压力0.1 MPa,空速3h-1,甲醇与苯进料比1∶1,此条件下苯的转化率可达51.36%,甲苯选择性为51.59%,二甲苯选择性为36.07%.ZSM-5 zeolite was prepared by alkali treatment,followed by modified with nickel nitrate and lanthanum nitrate by impregnation.The prepared samples were characterized by XRD,SEM,BET and NH_3-TPD,respectively.Then catalytic performance of benzene alkylation with methanol on the NiOLa_2O_3/ZSM-5 under different conditions was investigated.Results indicated modified NiO-La_2O_3/ZSM-5molecular sieve retaining the topology of MFI,however,a large amount of mesoporous structures were generated during the process.It had much weaker acid strength,less amount of strong acid sites,which was beneficial to alkylation of benzene with methanol.Tests also showed that the optimum reaction conditions of benzene alkylation over modified NiO-La_2O_3/ZSM-5molecular sieve came at the temperature of 450°C under the pressure of 0.1 MPa when the feed was introduced as the ratio of 1∶1at a space velocity of 3h-1.Under these conditions,conversion of benzene reached 51.36%,selectivity of toluene and xylene 51.59%,36.07%,respectively.

关 键 词：ZSM-5 镍 镧苯 烷基化 

分 类 号：O621.251[理学—有机化学]