NiMoS hydrocracking catalysts containing sulfur precursors calcined under various temperatures were prepared by kneading method,using ammonium tetrathiomolybdate and nickel nitrate as active components, and composite support composed of γ-Al2O3 and modified zeolite Y.The properties of catalysts were investigated by FT-IR, XRD and TEM.Test results indicated that with the increase of calcination temperature,the total acidity of the catalysts with sulfur precursors increased firstly and then decreased; more medium strong acid amount and higher B/L value were observed for these catalysts as compared with the oxidation state catalyst.The interactions between metal component and support in the catalysts containing ammonium tetrathiomolybdate as sulfur precursor were weakened, thus suitable crystal sizes and stacking numbers of active metal components could be obtained and the catalytic performances of the catalysts were improved.However, exceeded high calcination temperature was not in favor of forming suitable average crystal size and stacking number of MoS2 active phase.Catalyst with sulfur precursors calcined at 500 ℃ exhibited good hydrocracking performance: high conversion and liquid yield,as well as high selectivity and outstanding isomerization performance.%采用四硫代钼酸铵、硝酸镍为活性组分,从γ-Al2O3和改性Y分子筛的混合物为载体,通过混捏法制备不同焙烧温度的含硫前体NiMoS加氢裂化催化剂.对催化剂进行IR,TEM,XRD表征.结果表明:随焙烧温度的升高,含硫前体催化剂表面总酸量先增加后减小;含硫前体催化剂的中强酸酸量较大,且B酸量与L酸量之比也较大;由于以四硫代钼酸铵为前体的催化剂减少了金属与载体间的相互作用,有利于得到较佳的活性组分晶体尺寸和层数,从而提高了催化剂的性能;过高的焙烧温度不利于含硫前体催化剂活性相MoS2片晶形成合适的平均长度和平均层数;采用500℃焙烧的含硫前体催化剂进行加氢裂化反应时,产物的液体收率、转化率、选择性均较高,且异构性能突出.
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