We describe a highly nanodispersed Pd–MgO/SiO2 composite catalyst synthesized by an in situ, one-pot, reverse microemulsion method as a multifunctional catalyst for low-temperature CH4 reforming. Experimental results suggested evidence for a synergistic interplay of each component and DFT calculations confirmed a multifunctional reaction mechanism of CH4 reforming and the importance of the Pd–MgO interface. We find that the Pd nanoparticle binds and dissociates CH4, that MgO activates CO2 and increases coking resistance, and that SiO2 prevents Pd sintering. CO spillover from Pd to MgO opens a faster pathway for CO production. A unique and groundbreaking feature of the present catalyst is the well-designed cooperation of each element that assures long-lasting, consistent, high- and low-temperature activity.