热处理对铜基甲醇合成催化剂性能的影响

Effect of heat treatment on performance of Cu-based catalysts for methanol synthesis

采用共沉淀法制备了铜基甲醇合成催化剂,考察了4种焙烧条件对催化剂性能的影响,对催化剂进行了XRD、BET、EDS、SEM、TEM和H_(2)-TPR表征,测试了CO转化率和催化剂的热稳定性。结果表明:4种催化剂的结构组成基本一致。随着焙烧时间的延长,4种催化剂的CuO和ZnO平均晶粒尺寸逐渐变大,催化剂表面上元素均会发生团聚,Al_(2)O_(3)更容易结块团聚;焙烧时间延长还会使催化剂孔径分布发生变化。H_(2)-TPR表明2^(#)催化剂和3^(#)催化剂的Cu-Zn O结合紧密,表面CuO存在富集。活性测试表明焙烧30~40 min的催化剂活性最优。

The catalysts are prepared by coprecipitation method. The influence of four calcination conditions on the performance of the catalysts is investigated. The catalysts are characterized by XRD, BET, EDS, SEM, TEM and H_(2)-TPR. The conversion rate of CO and the thermal stability of the catalysts are tested. The results show that the structure of the four catalysts are basically the same. With the prolongation of calcination time, the average crystal size of CuO and ZnO of the four catalysts gradually increases, the elements on the surface of the catalysts will agglomerate, and the alumina is more likely to agglomerate. The distribution of pore size will change with the prolongation of calcination time. H_(2)-TPR showes that CuO is enriched on the surface of 2^(#) catalyst and 3^(#) catalyst. The activity test showes that the catalysts calcined for 30-40 min have the best activity.