溶胶-凝胶法制备Cu-ZnO-ZrO2催化剂:柠檬酸用量对催化剂性能的影响  

Preparation of Cu-ZnO-ZrO2 catalyst by sol-gel method:effect of citric acid content on catalyst performance

作　　者：闫晓峰 高文桂 毛文硕[1] 纳薇 霍海辉 常帅[1,2] YAN Xiaofeng;GAO Wengui;MAO Wenshuo;NA Wei;HUO Haihui;CHANG Shuai(Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction,Ministry of Education,Kunming 650093,Yunnan,China;Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China;State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,Kunming University of Science and Technology,Kunming 650093,Yunnan,China)

机构地区：[1]冶金节能减排教育部工程研究中心,云南昆明650093 [2]昆明理工大学冶金与能源工程学院,云南昆明650093 [3]昆明理工大学省部共建复杂有色金属资源清洁利用国家重点实验室,云南昆明650093

出　　处：《化工进展》2020年第10期4032-4040,共9页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51304099);国家重点研发计划(2018YFB0605402-02);昆明理工大学分析测试基金(2019M20172202082)。

摘　　要：采用溶胶-凝胶法以铜、锌、锆硝酸盐和柠檬酸为原料,改变柠檬酸用量,制备出一系列Cu-ZnO-ZrO2催化剂。通过X射线衍射仪(XRD)、热重分析仪(TG-DTG-DTA)、H2程序升温还原(H2-TPR)、CO2程序升温脱附(CO2-TPD)、红外光谱仪(FTIR)及BET比表面积等表征手段对干凝胶及催化剂理化性能进行测试,并在催化反应活性评价装置上对催化剂的CO2加氢合成甲醇反应活性进行评价,研究凝胶过程中Cu^2+、Zn^2+、Zr^4+与柠檬酸结合方式对催化剂性能的影响。结果表明:改变柠檬酸用量可调控Cu^2+、Zn^2+、Zr^4+与羧酸的配位方式,配位能力较强的Cu^2+、Zn^2+在凝胶制备过程中参与三维网络的构筑,而配位能力相对较弱的Zr^4+游离于三维网络之外,从而差异化地调控催化剂中活性组分CuO、ZnO、ZrO2晶粒尺寸大小。当柠檬酸的摩尔量为金属离子摩尔量的1.5倍时,催化剂中的活性成分CuO、ZnO、ZrO2晶粒尺寸相互匹配,表现出较好的CO2加氢合成甲醇催化性能。A series of Cu-ZnO-ZrO2 catalysts were prepared by the sol-gel method using copper,zinc,zirconium nitrate and different amounts of citric acid as raw materials.XRD,TG-DTA,H2-TPR,CO2-TPD,FTIR,and BET were used to characterize the physicochemical properties of the xerogel and the catalysts,and the catalytic activity of the catalysts for the hydrogenation of CO2 to methanol was evaluated.The effect of the coordination of Cu^2+,Zn^2+,Zr^4+with citric acid on the performance of the catalysts during the gelation was studied.The results showed that changing the amount of citric acid could regulate the coordination mode of Cu^2+,Zn^2+,Zr^4+with carboxylic acid.Cu^2+and Zn^2+with strong coordination ability can participate in the construction of three-dimensional network during the formation of gel,whereas Zr^4+was dissociated from the three-dimensional network,so the grain sizes of the active components of CuO,ZnO and ZrO2 in the catalyst can be regulated accordingly.When the molar amount of citric acid was 1.5 times of that of metal ions,the active components of CuO,ZnO and ZrO2 in the catalyst had compatible grain sizes,resulting in good catalytic performance for the hydrogenation of CO2 to methanol.

关 键 词：溶胶-凝胶 柠檬酸 二氧化碳 催化剂 甲醇 加氢 

分 类 号：O643.3[理学—物理化学]