Co2 +, Ni2+, Zn2+ and Al3+ quaternary hydrotalcite-type materials were synthesized at: 0.33; 0.25 and 0.20 (M3+)/(M3(+) + M2+) ratios. Then, these as-synthesized hydrotalcites were calcined and impregnated with Mo (15 wt.% MoO3) and Co (3Mo:Co) to obtain the catalytic precursors. As-synthesized and impregnated calcined hydrotalcites were characterized by different physico-chemical techniques such as: X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), BET surface area measurements and NH3-temperature programmed desorption (NH3-TPD). Finally, CoMo/calcined hydrotalcites were tested in hydrodesulfurization (HDS) and hydrogenation (HYS) reactions of thiophene and cyclohexene. Results showed that the 0.25 (M3 +)/(M3+ + M2+) ratio was the most active for the HDS reaction of thiophene, while the 0.33 (M3+)/(M3+ + M2+) ratio showed the best performance for the HYD reaction of cyclohexene. (C) 2015 Elsevier B.V. All rights reserved.