Deep desulfurization of gas oil over NiMo catalysts supported on alumina-zirconia composites

► NiMo/Al2O3-ZrO2 HDS catalysts containing 0, 2.5, 5 and 10 wt.% ZrO2 were studied. ► XRD patterns indicate homogenous dispersion of ZrO2 into Al2O3. ► NH3-TPD and CO chemisorption results show that ZrO2 generated a different type of stronger acid sites. ► HDS rate increased 1.3-2.5 times by incorporation of ZrO2 in support.