铈改性甲醇合成铜基催化剂的制备及其性能  

Preparation and properties of cerium modified Cu-based catalysts for methanol synthesis

作　　者：胡菊[1] 潘亚林[1] 黎汉生[1] 吴芹[1] 王金福[2] 

机构地区：[1]北京理工大学化工与环境学院,北京100081 [2]清华大学化学工程系,北京100084

出　　处：《化工学报》2014年第7期2770-2775,共6页CIESC Journal

摘　　要：采用反加共沉淀法,以硝酸铜、硝酸锌、硝酸铝溶液为原料,碳酸钠溶液为沉淀剂,硝酸铈为助剂,制备了铈(Ce)改性的甲醇合成铜基催化剂(CuZnAlCe),并通过X射线衍射(XRD)、N2等温吸附、热重-差热分析(TG-DTA)、扫描电子显微镜(SEM)、程序升温还原(TPR)等手段进行表征,采用微型固定床反应装置进行催化活性及稳定性评价,考察了Ce含量对CuZnAlCe催化剂结构和催化性能的影响。结果表明,Ce的引入可以改善催化剂活性中心的分散度,使催化剂比表面积增加,整体的结构变得更加松散,催化剂更容易被还原。随着Ce含量的增加,CO的转化率不断增大,当Ce含量为2%时CO转化率最大,可达47.6%。但Ce含量过量时使催化剂还原温度升高,CO的转化率降低。此外,适当的Ce含量改性可以提高铜基催化剂的热稳定性。Cerium modified Cu-based catalysts （CuZnAICe） for methanol synthesis from syngas were prepared by anti-coprecipitation method with Na2CO3 solution as a precipitant, Cu（NO3）2, Zn（NO3）2 and A12（NO3）3 solution as raw materials. The structure and morphology of CuZnAICe were studied by X-ray diffraction, thermal gravimetry-differential thermal analysis, N2 adsorption-desorption measurement, scanning electron microscopy, and temperature programmed reduction. The catalytic activities of the prepared catalysts for methanol synthesis were evaluated on micro fixed-bed reaction system. It showed that the addition of Ce improved the dispersion of active sites and provided a high surface area, which play an important role in the stability and activity of CuZnA1Ce. The CO conversion reached an optimum value to 47.6% over the Ce modified Cu-based catalyst at the Cu/Ce molar ratio of 1：0.02, while the catalytic activity and stability decreased when the loading of Ce was excessive. Proper loadings of Ce could improve the thermal stability of Cu-based catalysts.

关 键 词：反加共沉淀法 铈改性 铜基催化剂 甲醇合成 

分 类 号：O643[理学—物理化学]