Abstract: A silicon-containing alumina support, a process for preparing the support, and a catalyst containing the support are provided. The alumina support includes an additive silicon enriched on its surface, with the difference between the atomic ratio of silicon to aluminum on the surface of alumina support and that of the alumina support is at least 0.10. The process for preparing the silicon-containing alumina support comprises adding a nanometer silicon compound. The inventive alumina support can be used in manufacturing a catalyst for hydrotreating hydrocarbons with good physico-chemical properties and performance.

Abstract: The present invention relates to a highly active midbarrel hydrocracking catalyst and a process for the preparation thereof. The support of the catalyst comprises a modified zeolite-Y, a modified zeolite-&bgr;, alumina, etc. The composite of the modified zeolite-Y and zeolite-&bgr; exhibits a good synergistically catalytic effect. The catalyst prepared by supporting Group VIB and/or Group VIII metal components is useful in the hydrocacking of heavy oils with high content of sulfur and nitrogen to produce high quality middle distillates with maximum output. The activity of and selectivity to middle distillates of the catalyst are remarkably raised simultaneously. Moreover, the solidifying point of the produced diesel is remarkably lowered.