Y_2P_2W_(18)O_(62)·nH_2O/MWCNTs催化剂的制备及其催化合成乙酸正丁酯  

Preparation of Y_2P_2W_(18)O_(62)·nH_2O/MWCNTs and its catalytic performances in synthesis of n-butyl acetate

作　　者：曹小华[1,2] 陶春元[1,3] 谢宝华[3] 

机构地区：[1]江西省生态化工工程技术研究中心,江西九江332005 [2]九江学院功能有机分子制备与应用九江市重点实验室,江西九江332005 [3]九江学院化学与环境工程学院,江西九江332005

出　　处：《石油化工》2016年第2期200-205,共6页Petrochemical Technology

基　　金：国家自然科学基金项目(21161009);江西省教育厅科技项目(GJJ14731;GJJ12616);九江学院科技项目(2013KJ005)

摘　　要：以Dawson型磷钨酸钇(Y_2P_2W_(18)O_(62)·nH_2O)为活性组分,多壁碳纳米管(MWCNTs)为载体,通过浸渍法制备了负载型磷钨酸钇催化剂。利用FTIR,XRD,SEM,TG,Py-IR,NH3-TPD,N2吸附-脱附等手段对催化剂进行表征,考察了催化剂催化正丁醇与乙酸液相反应合成乙酸正丁酯的性能。表征结果显示,催化剂具有Dawson结构,且同时具有Br觟nsted酸中心和Lewis酸中心,与Y_2P_2W_(18)O_(62)·nH_2O相比,催化剂出现了弱酸中心,总酸量减小,催化剂的比表面积及热稳定性均明显提高。实验结果表明,在n(正丁醇)∶n(乙酸)=2.0∶1.0、催化剂用量为反应物的1.7%(w)、反应温度125℃、反应时间2.0 h的条件下,酯化率为97.4%。催化剂重复使用5次时,酯化率仍可达80.7%。Dawson type yttrium phosphotungstate（Y2P2W18O62·nH2O） supported on multiwalled carbon nanotubes（MWCNTs） was prepared through impregnation and was characterized by means of FTIR, XRD, SEM, TG, Py-IR, NH3-TPD and N2 adsorption-desorption. The synthesis of n-butyl acetate from acetic acid and n-butanol over Y2P2W18O62·nH2O/MWCNTs was investigated. The results showed that Y2P2W18O62·nH2O still kept its Dawson structure after the supporting. There were both Bronsted and Lewis acid sites on Y2P2W18O62·nH2O/MWCNTs. By loading Y2P2W18O62·nH2O on MWCNTs, the specific surface area and thermostability were enhanced, but the acid strength and total acidity decreased. Under the optimal reaction conditions of mass ratio of catalyst to reactants 1.7%（w）, molar ratio of n-butyl alcohol to acetic acid 2.0 ： 1.0, temperature 125 ℃ and reaction time 2.0 h, the esterification rate reached 97.4%. The esterification rate still reached 80.7% when the catalyst was reused 54 times.

关 键 词：Dawson型磷钨酸钇 多壁碳纳米管 负载型催化剂 正丁醇 乙酸 乙酸正丁酯 

分 类 号：TQ426.6[化学工程]