Au-Ni/SiO_2双金属催化剂的噻吩加氢脱硫活性

Au-Ni/SiO_2 Bimetallic Catalyst for Thiophene Hydrodesulfurization

采用分步浸渍法制备了Au-Ni/SiO_2双金属催化剂,以含体积分数1%噻吩的正己烷为原料,考察了Au与Ni负载量(质量分数)、硫化温度与硫化时间、反应温度、液态空速、氢气与原料油的体积比(氢油比)等因素对Au-Ni/SiO_2催化剂加氢脱硫活性的影响;采用N_2吸附和TPR方法对Au-Ni/SiO_2催化剂进行了表征。实验结果表明,Au-Ni/SiO_2催化剂中Au和Ni的负载量均对催化剂的加氢脱硫活性有一定影响,Au的加入明显提高了催化剂的加氢脱硫活性;硫化程度较高的Au-Ni/SiO_2催化剂具有较好的加氢脱硫活性;Au-Ni/SiO_2催化剂的比表面积及孔结构不是影响该催化剂活性的主要因素;Au和Ni的负载量分别为1.5%和5.0%的Au-Ni/SiO_2催化剂在400℃下硫化120min,在常压、反应温度400℃、液态空速低于3.6h^(-1)、氢油比2000的条件下具有良好的加氢脱硫活性。

Au-Ni/SiO2 bimetallic catalysts, which might be used in hydrodesulfurization （HDS） of thiophene in fuel oil, were prepared through a consecutive impregnation method. Effects of the Au and Ni loadings, sulfidation temperature and time of catalyst, and reaction conditions on the catalyst activities in the HDS under atmospheric pressure were studied. The catalyst was characterized by means of N2 physical adsorption and TPR with hydrogen. The results revealed that the presence of Au improved activity of Ni/SiO2 catalyst in the HDS. The higher the sulfidation degree of the catalyst was, the higher its activity in the HDS was. Textural properties of the Au-Ni/SiO2 catalyst were not main influencing factors to its activity in the HDS. The optimal conditions for the Au-Ni/SiO2 catalyst sulfidation were： Au loading 1.5%, Ni loading 5.0%, sulfidation temperature 400℃ and sulfidation time 120 min. The optimal conditions for the HDS of thiophene in 1% （φ） thiophene/hexane as liquid feed were： normal pressure, reaction temperature 400 ℃, LHSV 3.6 h^-1 or lower and volume ratio of hydrogen to liquid feed 2 000.