H_2S/H_2硫化温度对MoP/SiO_2催化剂硫醚化性能的影响

Effect of H_2S/H_2 sulfuration temperature on performance of MoP/SiO_2 catalyst for thioetherification

以负载磷酸钼为前驱体,采用程序升温还原法制备了MoP/SiO_2催化剂,以体积分数3%H_2S/H_2对其进行了硫化处理,利用XRD、CO化学吸附、NH_3-TPD、HRTEM-EDX、ICP-AES以及XPS等手段对催化剂进行了表征,研究了硫化温度对MoP/SiO_2催化剂结构和异戊二烯与正丁硫醇硫醚化性能的影响。结果表明,即使在400℃硫化处理也未改变MoP/SiO_2催化剂中MoP体相结构;随着硫化温度提高,催化剂表面酸量增加、金属位数量减少,降低了催化剂C-S键氢解及异戊二烯深度加氢活性,但同时也提高了催化剂烯烃聚合活性。经120℃硫化处理的MoP/SiO_2兼具较佳硫醚化及异戊二烯选择加氢性能。

The MoP/SiO2 catalyst was prepared from the supported M o phosphate by the H2-TPR method and treated with 3% H2S/H2 at different temperatures. The as-prepared catalysts were characterized by means of XRD,HRTEM-EDX,XPS,NH3-TPD,ICP-AES and CO chemisorption and tested for the thioetherification of isoprene and n-butylmercaptan. The effects of sulfuration temperature on the MoP/SiO2 catalyst structure and thioetherification performance were investigated. The results showed that the M oP phase was still stable even at the sulfuration temperature of 400 ℃. As the sulfuration temperature increased,the acid amount of the catalysts increased while the surface metal site density decreased. As a result,in the thioetherification of isoprene and nbutylmercaptan,the C-S bond hydrogenolysis and the over-hydrogenation of isoprene were suppressed on the sulfurized catalysts,while the olefin polymerization was promoted. Relatively,the MoP/SiO2 catalyst sulfurized at 120 ℃ had better performance for the thioetherification and the selective hydrogenation of isoprene.