活性炭基水解催化剂的制备及其脱硫性能的研究

摘要

Cu/AC hydrolysis catalysts were prepared by sol-gel method and impregnation method,and the influence of the preparation methods on their desulfurization activities were investigated.XRD,BETand SEM were used to characterize the support and the catalysts.The influence of surface pretreatment and preparation methods on their desulfurization activities and the mechanism of hydrolysis desulfurization were discussed.The results showed that the desulfurization activity of the catalyst prepared by impregnation method is better than that prepared by sol-gel method.By expanding the specific surface area and increasing the number of pores of activated carbon in the process of pretreatment,the catalyst which was prepared by impregnated method can be uniformly dispersed on the surface of carrier and also into its pores.On the contrast,the catalyst prepared by sol-gel method resulted in active component dispersing only on the surface of activated carbon,leading to low desulfurization efficiency.Under the temperature of 80℃,1.33g/m3 of COS concentration,1500h-1 of space velocity,5％ of mass fraction copper oxide,Cu/AC hydrolysis catalyst prepared by impregnation method exhibits the highest sulfur capacity of 29mgS/g.%分别通过溶胶-凝胶法、浸渍法制备Cu/活性炭(AC)水解催化剂,考察了不同制备方法对水解脱硫性能的影响.利用XRD、BET、SEM等对载体及催化剂进行表征,分析了预处理对AC表面性质及不同制备方法对脱硫效率的影响,并探讨了水解脱硫的机理.结果表明,浸渍法所制备的水解催化剂活性优于溶胶-凝胶法制备的催化剂,在通过预处理增大了AC的比表面积、丰富了AC的孔道结构的基础上,浸渍法能均匀地将活性组分分散在载体表面及其孔道中,而溶胶-凝胶法制备的催化剂活性组分主要覆盖在载体的表面,不能有效进入孔道内,造成脱硫效率下降.在反应温度80℃、羰基硫浓度1.33g/m3、空速1500h-1、氧化铜质量分数为5％时,浸渍法制备的水解催化剂具有较高的硫容,可达29mgS/g.