溶剂极性对微波辐射老化制备前驱体及CuO/ZnO/Al_2O_3催化剂结构的影响  

Influence of Solvent Polarity on Microstructure of Precursors and CuO/ZnO/Al_2O_3 Catalysts Aged under Microwave Irradiation

作　　者：崔晓曦[1] 范辉 郑华艳[1] 李忠[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 [2]赛鼎工程有限公司,技术中心,太原030024

出　　处：《无机化学学报》2012年第3期495-502,共8页Chinese Journal of Inorganic Chemistry

基　　金：山西省回国留学人员科研基金(No.201038)资助项目

摘　　要：在制备CuO/ZnO/Al2O3催化剂的老化过程中,采用微波辐射老化技术,着重研究了溶剂极性对前躯体物相组成,烧后CuO/ZnO/Al2O3催化剂结构及其在浆态床合成甲醇工艺中催化性能的影响。通过XRD、DTG、H2-TPR,FTIR、HR-TEM和XPS对前驱体及催化剂表征表明,沉淀母液在微波辐射条件下进行老化,溶剂的极性对前躯体物相组成及催化剂结构影响显著。随着溶剂极性的增大,Zn2+/Cu2+取代Cu2(CO3)(OH)2/Zn5(CO3)2(OH)6中Cu2+/Zn2+的取代反应增强,使得前躯体中(Cu,Zn)5(CO3)2(OH)6和(Cu,Zn)2(CO3)(OH)2物相的含量增多,结晶度提高,导致烧后CuO/ZnO/Al2O3催化剂中CuO-ZnO协同作用增强,且CuO晶粒减小,表面Cu含量增加,催化剂活性和稳定性提高。水溶剂的极性最大,制备的催化剂活性和稳定性最好,甲醇的时空收率(STY)和平均失活率分别为320 mg.g-1.h-1和0.11%.d-1。In the preparation of a CuO/ZnO/Al2O3 catalyst for slurry methanol synthesis,microwave irradiation was introduced into the aging process.The effect of solvent polarity was studied on phase composition of the precursor,microstructure of the calcined CuO/ZnO/Al2O3 catalyst and catalytic performance for slurry methanol synthesis.The characterization by XRD,FTIR,DTG,HR-TEM,H2-TPR and XPS showed that the solvent polarity had a significant effect on the composition of the precursor aged under microwave irradiation.The results indicated that solvent polarity benefited to the substitution of Cu2＋/Zn2＋ in Cu2（CO3）（OH）2/Zn5（CO3）2（OH）6 by Zn2＋/Cu2＋.With the increasing of the solvent polarity,the content and crystallization degree of（Cu,Zn）2（CO3）（OH）2 and（Cu,Zn）5（CO3）2（OH）6 became higher in the precursor,the interaction of CuO/ZnO/Al2O3 between CuO and ZnO became stronger,CuO crystal particles dispersed better and surface CuO content became higher.The performance of CuO/ZnO/Al2O3 catalyst using water as solvent is the best,the methanol sapce-time yield（STY） and deactivation rate of the catalyst were 320 mg· g-1·h-1 and 0.11%·d-1,respectively.

关 键 词：微波辐射 溶剂极性 甲醇合成 浆态床 CuO/ZnO/Al2O3催化剂 

分 类 号：O643[理学—物理化学]