氮、磷、碳化物比较研究初探

环保法规的日益严格使得研究者越来越重视新型加氢脱硫、脱氮催化剂的开发。国内外学者在对负载型Mo—Co、Mo—Ni和W—Ni等传统硫化物催化剂进行不断改进的同时，新型催化材料尤其是具有贵金属性质的过渡金属间充化合物一氮化物、碳化物和磷化物的研究也受到很大的关注。人们在探索不同的载体或者是不同的助剂对单金属间充化合物-氮化物、碳化物或磷化物催化剂活性组分的表面状态和结构以及其深度加氢脱硫脱氮性能的影响，而对同一载体负载的氮、磷、碳化物催化剂缺乏横向的比较。本研究制备了以γ-Al2O3为载体的负载型氮化钼、磷化钼和碳化钼催化剂，比较了它们的孔结构、比表面积，并初步分析了钼的质量分数为19％，氮化、磷化和碳化温度均为650℃时三类催化剂的二苯并噻吩加氢脱硫性能。

Comparative study on molybdenum nitride, phosphide and carbide

γ-Al2O3 supported molybdenum nitride, molybdenum phosphide and molybdenum carbide catalysts for hydrodesulphurization were prepared, respectively, by temperature-programmed reaction. The precursors were obtained by impregnation of γ-Al2O3 in an aqueous solution of ammonium heptamolybdate tetrahydrate (NH4)6Mo7O24·4H2O] and diammonium hydrogen phosphate (NH4)2HPO4], followed by drying at 120℃ and calcining at 500℃ in air. The three kinds of catalysts were characterized by XRD and BET. The results indicated that the molybdenum carbide prepared at a space velocity (CH4H2) of 10800h－1 has the biggest surface area of 175.7m2/g. The pore size distribution of molybdenum nitride catalyst was complex. The small pores of about 0.6225nm and the big pores of about 3.736nm were mainly observed in the supported molybdenum nitride catalyst. The active components in all of the three catalysts were dispersed on γ-Al2O3 uniformly. The conversion of dibenzothiophene on the three catalysts could respectively reach 85.5%、81% and 78.6%.