Ni catalysts supported on MgOSiO2 were assessed in the steam reforming reaction of glycerol for the study of the H2 production and carbon deposition with different MgO contents as additives. The catalysts were prepared with commercial SiO2 by the aqueous impregnation method and characterized by energy dispersive X-ray spectroscopy, specific surface area, X-ray diffraction, thermogravimetric analysis, X-ray diffraction in situ with O2, temperature programmed reduction with H2, X-ray diffraction in situ with H2, temperature programmed desorption with H2 and scanning electron microscopy. The glycerol steam reforming reaction took place at 600 °C for 5 h, with a water/glycerol molar ratio of 12/1 at 5 mLh−1. N2 was used as the carrier gas. The characterization of the samples showed the interaction of Ni with the support increases with the MgO addition, due to the formation of a NiMg silicate hydrate and MgNiO2 solid solution; as a result, both metallic area and dispersion also increased. Catalytic results showed similar gaseous products yields (H2, CH4, CO and CO2) for mixed-matrix catalysts, however, a lower carbon deposition on 10 wt%Ni catalyst supported on 30 wt%MgOSiO2 was observed.