MCM-41负载Dawson型磷钨酸的制备及其对乙酸与正丁醇酯化反应的催化性能研究  

Preparation of H_6P_2W_(18)O_(62)/MCM-41 and its catalytic performances for esterification reaction of acetic acid with n-butanol

作　　者：周德志[1] 肖彬 曹小华[1] 徐常龙[1] 占昌朝[1] ZHOU De-zhi;XIAO Bin;CAO Xiao-hua;XU Chang-long;ZHAN Chang-chao(College of Chemical and Environmental Engineering,Jiujiang University,Jiujiang 332005, China;Suichuan No. 2 high School,Jian 343927, China)

机构地区：[1]九江学院化学与环境工程学院,江西九江332005 [2]江西省遂川县第二中学,江西吉安343927

出　　处：《化学研究与应用》2018年第5期773-778,共6页Chemical Research and Application

基　　金：国家自然科学基金项目(51562016;21161009)资助;江西省自然科学基金项目(20171BAB206015)资助;江西省教育厅科技项目(GJJ12616)资助

摘　　要：以MCM-41为载体,H_6P_2W_(18)O_(62)为活性组分,通过浸渍法制备出负载型催化剂40%H_6P_2W_(18)O_(62)/MCM-41,对催化剂进行FT-IR、XRD、SEM、EDX、NH3-TPD和TG表征。XRD、SEM测试结果表明H_6P_2W_(18)O_(62)均匀地负载MCM-41载体上,FT-IR、EDX测试表明负载后H_6P_2W_(18)O_(62)仍保持Dawson结构不变,NH3-TPD、TG结果表明负载后催化剂出现弱酸中心,同时强酸中心酸强度和酸量均增多,催化剂热稳定性显著提高。以40%H_6P_2W_(18)O_(62)/MCM-41为催化剂,催化乙酸和正丁醇合成乙酸正丁酯。考察了催化剂用量、醇酸摩尔比、反应时间和反应温度对酯化率的影响。结果表明:40%H_6P_2W_(18)O_(62)/MCM-41在催化合成乙酸正丁酯反应中表现出优异的催化活性,最优条件为:n(正丁醇)∶n(乙酸)=2.0∶1.0,w(40%H_6P_2W_(18)O_(62)/MCM-41)=3.7%(基于反应物质量),反应温度125℃,反应时间3.0 h。在此条件下乙酸正丁酯的收率达到了97.5%,催化剂重复使用5次时,酯化率仍可保持为72.1%。Supported catalyst 40% H6P2W18O62/MCM-41 was prepared by impregnation method with MCM-41 as the carrier and H6 P2 W^s 062 as the active component. The catalyst was characterized by FT-IR, XRD, SEM, EDX, NH3 -TPD and TG. SEM and XRD analysis showed that H6P2W18O62 well dispersed in MCM-41. FT-IR and EDX study indicated that the Dawson structure of phospho- tungstie acid remains during loading H6P2W18O62 on MCM-41. Results of NH3-TPD and TG reveald that 40% H6P2W18O62/MCM- 41 exist weak acid sites, and the acid strength and acid amount of strong acid sites were largely increased. The thermal stability- of 40% H6P2W18O62/MCM-41 could be markedly improved too. The catalytic activities of 40% H6P2W18O62/MCM-41 for esterifieation of acetic acid and n-butanol had been investigated. The effects of catalyst dosage, molar ratio of acid to alcohol, reaction time and re- action temperature on the esterifieation rate were investigated. The catalyst exhibited high esterifieation reaction catalytic activity and the highest esterifieation rate was up to 97. 5 % under the optimal reaction eonditions,i, e. , molar ratio of n-butanol to acetic acid of 2.0, the mass ratio of catclyst to total reactant of 3.7% , reaction temperature of 125℃, reaction time of 3.0 h. The catalyst could be reused for 5 times with esterification rate of above 72. 1%.

关 键 词：Dawson型磷钨酸 H6P2W18062/MCM-41 负载型催化剂 催化酯化 乙酸正丁酯 

分 类 号：O614.33[理学—无机化学]