Co-Mo/Al2O3 commercial catalytic used wetness impregnation method to prepare Co-Mo B/Al2O3 and Co-Mo P/Al2O3. We study the characterization of this catalyst which contains 12.0 wt. % Mo and 4.0 wt. % Co in γ-Al2O3 and gave the higher surface area of 192 m2/g.
The effects of boron and phosphores addition on the HDS and HDA of heavy gas oil over CoMo/g-Al2O3 catalysts have been studied. The addition of boron slightly improves the acidity of the acid sites, Thus, the catalytic hydroprocessing activities of heavy gas oil over the CoMo/g-Al2O3 catalysts may be related to the acidity and metal dispersion of the catalysts. Furthermore, the addition of phosphorus improves the dispersion of Co and Mo species, which also enhance the
catalytic performance. Also, the addition of phosphorus caused the formation of acid centers.