Amorphous silica-alumina, a carrier combination and a hydrocracking catalyst containing the same, and processes for the preparation thereof

摘要

An acidic amorphous silica-alumina having large specific surface area and a large pore volume, a carrier complex and a hydrotreating catalyst containing said acidic amorphous silica-alumina, in particular a hydrocracking catalyst containing said acidic amorphous silica-alumina in combination with a modified zeolite-Y for treating petroleum hydrocarbon materials to produce middle distillates, and processes for the preparation thereof. Said amorphous silica-alumina has a SiO₂ content of 10-50 wt %, a specific surface area of 300-600 m²/g, a pore volume of 0.8-1.5 ml/g and an IR acidity of 0.25-0.60 mmol/g. The catalyst according to the present invention shows a relatively high activity and mid-distillate selectivity and can be particularly used in hydrocracking process for producing mid-distillates in a higher yield.