微波辐射对浆态床合成甲醇CuO/ZnO/Al_2O_3催化剂前驱体晶相转变的影响  

Influence of Microwave Irradiation on Phasetransition in Preparation of Precursor of CuO/ZnO/Al_2O_3 Catalysts for Slurry Methanol Synthesis

作　　者：范辉[1] 李忠[1] 郑华艳[1] 刘岩[1] 闫少伟[1] 

机构地区：[1]太原理工大学煤化工研究所煤科学与技术教育部和山西省重点实验室,太原030024

出　　处：《无机化学学报》2011年第3期509-518,共10页Chinese Journal of Inorganic Chemistry

基　　金：国家重点基础研究发展计划(973)(No.2005CB221204)资助项目

摘　　要：在微波辐射条件下,对CuO/ZnO/Al2O3催化剂的沉淀母液进行老化,通过XRD、TG、H2-TPR,FTIR、HR-TEM和XPS对前驱体及催化剂微观结构的进行表征,探讨了CuO/ZnO/Al2O3催化剂前驱体晶相转变过程中微波辐射的作用。结果表明,微波辐射有利于Cu2+取代Zn5(CO3)2(OH)6中Zn2+的同晶取代反应。微波辐射的老化过程中,首先发生Cu2+取代Zn5(CO3)2(OH)6中Zn2+生成(Cu,Zn)5(CO3)2(OH)6的同晶取代反应,并于1.0 h内基本完成;随着老化时间继续延长,主要进行Zn2+取代Cu2(CO3)(OH)2中Cu2+生成(Cu,Zn)2(CO3)(OH)2的同晶取代反应,同时(Cu,Zn)5(CO3)2(OH)6进一步结晶。与常规老化1 h制备的前驱体相比,微波辐射老化1.0 h制备的前驱体含有较多的(Cu,Zn)5(CO3)2(OH)6物相,有助于增强焙烧后CuO/ZnO/Al2O3催化剂中CuO-ZnO协同作用,提高表面铜含量,进而提高CuO/ZnO/Al2O3催化剂在浆态床合成甲醇的催化活性和稳定性,在400 h浆态床合成甲醇评价期间,甲醇时空收率最大达318.9 g.kg-1.h-1,失活率仅为0.11%.d-1。The microwave irradiation was used in the aging process of CuO/ZnO/Al2O3 catalyst precursor.XRD,FTIR,TG,H2-TPR,HR-TEM and XPS were used to examine the microstructure of precursor and the CuO/ZnO/Al2O3 catalyst and investigate the effect of the microvave irradiation on precursor phase transition.The results show that microwave irradiation during the aging process promots the substitution of Zn2＋ in the Zn5（CO3）2（OH）6 compound by Cu2＋.During aging process under microwave irradiation,the substitution of Zn2＋ in Zn5（CO3）2（OH）6 compound by Cu2＋ firstly occurs and completes within 1 h.The Cu2＋ in Cu2CO3（OH）6 compound is constantly substituted by Zn2＋ with the increasing of aging time,meanwhile,the crystallization degree of（Cu,Zn）5（CO3）2（OH）6 becomes higher.Compared with the precursor aged for 1 h without microwave irradiation,the precursor aged for 1 h under microwave irradiation possesses higher content of（Cu,Zn）5（CO3）2（OH）6,the calcined catalysts show strong interaction between CuO and ZnO,well dispersed CuO crystal particles,and high surface CuO content,the methanol space-time yield（STY） and deactivation rate of the catalyst were 318.9 g·kg-1·h-1 and 0.11%·d-1,respectively.

关 键 词：微波辐射 甲醇 浆态床 CuO/ZnO/Al2O3催化剂 

分 类 号：O614.121[理学—无机化学] O614.24[理学—化学]