超声波对制备Co-Fe/硅藻土选择加氢催化剂的影响

Influence of Ultrasonic on Preparation of Co-Fe/Diatomite Catalysts for Selective Hydrogenation

分别在有无超声条件下,采用分步浸渍法制备了负载型Co-Fe/硅藻土催化剂,以肉桂醛选择加氢为肉桂醇为探针反应,在固定床微分反应器上考察了催化剂的活性.采用热分析、红外、XRD及正电子寿命谱等技术分析了催化剂的催化性能及超声波对活性的影响.结果表明,经超声处理的催化剂对肉桂醛加氢为肉桂醇转化率、选择性和收率明显提高.超声处理没有改变催化剂载体的结构,但使主、助催化剂更好地分散在载体上,使催化剂表面的两类缺陷尺寸变小,同时增加第二类缺陷数量,有更好的催化活性.

Supported Co-Fe/Diatomite catalysts were prepared by step-by-step impregnation method with and without ultrasonic. The activities of Co-Fe/diatomite catalysts were investigated by the selectivity hydrogenation of cinnamaldehyde to cinnamyl alcohol in a fixed-bed differential reactor. The catalytic hydrogenation activity and the influence of ultrasonic to catalytic activity were studied by thermal analysis, IR, XRD and positron life spectra. The results reveal that the conversion, selectivity , and yield of selective hydrogenation cinnamaldehyde to cinnamyl alcohol were significantly improved after the Co-Fe/Diatomite catalyst treated by ultrasonic. Ultrasound treatment did not change the main configuration of catalyst supporter, but ultrasound made main and promoter catalyst to better spread on the supporter, so that the sizes of the two types defect on catalyst surface become smaller, the second type of defects increased, and the Co-Fe/Diatomite catalyst had a better catalytic activity.