酸-碱交替沉淀法制备铜基甲醇合成催化剂  

Preparation of Copper-Based Catalysts for Methanol Synthesis by Acid-Alkali-Based Alternate Precipitation Method

作　　者：岑亚青[1] 李小年[1] 刘化章[1] 

机构地区：[1]浙江工业大学工业催化研究所绿色化学合成技术国家重点实验室培育基地,浙江杭州310032

出　　处：《催化学报》2006年第3期210-216,共7页

摘　　要：采用酸-碱交替沉淀法（AP法）制备了一种新型的低压甲醇合成催化剂. 研究了母液pH值和交替次数对催化剂性能的影响. 结果表明, pH值交替范围为5.0～9.5, 交替次数为3时制备的催化剂活性最好. 与其它制备方法相比, AP法制备的催化剂具有最高的活性和耐热性,耐热后活性保留率达88%, 比其它催化剂高8%～20%, 而且耐热后活性甚至高于其它催化剂的初活性. X射线衍射（XRD）、热重分析、低温N2吸附和扫描电子显微镜等结果表明, AP法制备的催化剂的XRD谱中铜和锌的特征峰最为宽化、弥散, CuO与ZnO 峰交织在一起,峰强度最弱;同时催化剂的粒度较小,粒径尺寸分布较均匀,结晶度相对较低;而且催化剂的还原温度最低,铜锌组分间的协同作用最强. 这表明AP法制备的催化剂具有高活性、高耐热性和易还原的主要原因是该制备方法使催化剂中的铜锌组分形成了无定形状态的铜锌固溶体,提高了活性组分的分散度和比表面积.A new copper-based catalyst for methanol synthesis was prepared by acid-alkali-based alternate precipitation （AP） method. The catalyst activity is the highest when the pH value of the mother solution alters in the range of 5.0 and 9.5 for three times. Compared with the catalysts prepared by other methods, the activity and thermal stability of the catalyst prepared by the AP method is the best. About 88 % activity of the catalyst is remained after the thermal test, which is 8 % - 20 % higher than that of other catalysts. Furthermore, the activity of this catalyst after the thermal test is higher than that of other catalysts before the thermal test. The catalysts were characterized by X-ray diffraction （XRD）, N2 adsorption, differential thermogravimetric analysis （DTG）, and scanning electron microscopy （SEM）. XRD patterns show that the characteristic peaks of CuO and ZnO are far more broadened for the catalyst prepared by the AP method. From SEM photographs it is found that the grains of the catalyst prepared by the AP method are smaller, and the distribution of the grains is symmetrical. The crystal size of this catalyst is small. DTG patterns show that this catalyst requires the lowest reduction temperature. The primary reason for the high activity and thermal stability of the catalyst prepared by the AP method is that an amorphous sosoloid of CuO and ZnO is formed, which can increase the dispersion of the active components and the BET surface area of the catalyst.

关 键 词：甲醇合成 铜基催化剂 酸-碱交替沉淀法 

分 类 号：O643.36[理学—物理化学]