Glycerol and glycerol/water solution were converted to syngas over Pt-, LaMnO3-, and Pt/LaMnO3-coated monoliths under autothermal partial oxidation. XRD and SEM were used to characterize the phase compositions and surface morphologies of freshly prepared and postreaction catalysts. A continuous fixed-bed design, without an upstream vaporizer or external heat supply, was operated at millisecond contact times. Among the catalysts used in this study, Pt was the least reactive, and its activity was found to be reduced by sintering. Pt also tended to produce nonequilibrium products such as ethylene and acetaldehyde in fuel-rich environments. In contrast, LaMnO3 was found to favor glycerol combustion, producing fewer minor products and generating sufficient heat to sustain autothermal operations in fuel- and steam-rich regimes. Pt supported on LaMnO3 showed a synergistic effect of Pt sintering suppression and a broad H-2/CO distribution in the resulting syngas. This effect can be correlated to the interaction between Pt and LaMnO3.