研究了新型固体硫化剂硫代硫酸铵对加氢脱硫催化剂的预硫化。采用浸渍法将硫代硫酸铵负载在Mo/Al2O3模型催化剂上制备出预硫化的催化剂。通过X射线衍射、还原气氛的热重质谱联用和光电子能谱等表征手段研究了预硫化催化剂的物相、活化以及反应后催化剂的表面成分。结果表明,硫代硫酸铵中不同价态的硫在催化剂活化过程中起到不同作用,S^2-硫化活性金属,S^6+修饰载体,减少载体与活性金属的相互作用,促进硫化。不同S/Mo摩尔比的预硫化催化剂经原位氢气活化用于噻吩加氢脱硫反应,S/Mo摩尔比为3的预硫化催化剂显示出最好的加氢脱硫活性,预硫化催化剂比Mo/Al2O3催化剂的脱硫活性提高17%。
Ammonium thiosulfate as a novel sulfiding agent was used for presulfidation of hydrodesulfurization (HDS) catalysts. The presulfided Mo/Al2O3 catalysts with different molar ratios of S/Mo were prepared by impregnating Mo/Al2O3 catalysts with an aqueous solution of ammonium thiosulfate, followed by drying. Their characteristics of crystal phases, activation, and surface compositions were examined by X-ray diffraction, thermogravimetric analysis, and X-ray photoelectron spectroscopy. The S^2- and S^6+ in ammonium thiosulfate play different roles during the activation of presulfided catalysts. The S^2- sulfides Mo and S^6 + reacts with Al2O3 support, decreasing the interaction of support with the active metal. The collaboration between S^2- and S^6 + ions improves the sulfidation of MoO3. The best HDS performance was observed for the presulfided catalyst with S/Mo = 3. Its thiophene HDS activity is 17% higher than that of Mo/Al2O3 catalyst sulfided with H2S.