Co-x-Co(2)Mow/SiO2 and Co2Mo10/Co-x/SiO2 catalysts with various Co/Mo ratios and active species compositions are prepared using H-6[Co2Mo10O38H4] heteropolyacid, CoCO3 and citric acid. Catalysts are characterized using the following techniques: low-temperature N-2 adsorption, temperature-programmed reduction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Catalytic activities of the synthesized catalysts are examined in hydrotreating of model fluid catalytic cracking (FCC) gasoline that contains 1000 ppm of sulphur from thiophene and 36 wt.% of n-hexene-1. As the Co/Mo ratio increases, hydrodesulphurization (HDS) and hydrogenation (HYD) activities of the prepared catalysts significantly builds up. The changes of catalytic properties and specifically of the HDS/HYDO selectivity factor of the synthesized CoMo catalysts arise from two effects: an alteration of the promotion degree of CoMoS active phase particles and a hydrogen spillover from CoSx species to active sites. The developed silica-supported CoMo catalysts may be a prospect for selective HDS and hydro-upgrading of FCC gasoline. (C) 2016 Elsevier B.V. All rights reserved.