利用共沉淀法制备了四组分的Cu Zn Al Mn和Cu Zn Al Ce催化剂以及三组分的Cu Zn Al催化剂。利用组成H2/CO/CO2/N2=66/27/3/4(体积比)的富CO原料气对催化剂进行了活性评价,并研究了温度、压力和空速等反应条件对催化剂活性的影响。结果发现添加适量的锰助剂能显著提高催化剂的活性和热稳定性。利用SEM和XRD方法进行了催化剂的结构和形貌表征,同样表明锰助剂可以起到阻止CuO晶粒长大和促进CuO分散作用。利用富CO2的生物质原料气体积比为H2/CO/CO2/N2=50/25/20/5对Cu Zn Al Mn催化剂进行的评价表明:Cu Zn Al Mn催化剂上CO/CO2加氢合成甲醇的甲醇产率和选择性均有下降,在试验范围内,甲醇产率下降11%～25%,选择性为93%～95%。
In view of not uniformity in conventional coprecipitation preparation, urea was used as the precursor of precipitator to prepare Cu/ZnO/Al2O3 catalysts for methanol synthesis. In the method, urea was dissolved in nitrate solution and hydrolyzed to produce OH- as precipitator after the solution was heated to 90℃. After 6h, the precipitation was accomplished. The evaluation results of the catalyst activity showed that this catalyst had comparable catalytic activities to the industrial catalyst, and reached its maximum activity at 250℃. At reaction conditions of 250℃, 3MPa,and SV=7600h-1, the STY of methanol was 0.38g/（mL·h） with syngas compositing of H2,CO, CO2, and N2 atmolar ratio of 65.9∶27.1∶2.9∶4.1. X-ray Diffraction （XRD） revealed that the particle size of CuO and ZnO was about 200nm, and Al existed in the form of ZnAl2O4 spinel in the catalysts.
