Catalytic carbon combustion is a potential approach for eliminating particulate matter emissions from diesel engine vehicles. In this study, we report low-temperature carbon combustion by active oxygen formed at the interface of the mixed powders of a proton conductor (Sn0.9In0.1P2O7) and electrocatalyst (Pt or Mo2C). In a gaseous mixture of H2O and O-2, H2O dissociated into protons and electrons at an anodic site of the interface and the resultant active oxygen oxidized carbon to CO2. Separately, O-2 reacted with protons and electrons to form H2O at a cathodic site of the interface, resulting in formation of a local electrochemical cell at the proton conductor electrocatalyst interface, which then self-discharged. This series of reactions could successfully reduce the ignition temperature for carbon to 200 degrees C for Pt and 300 degrees C for Mo2C. (C) 2010 Elsevier B.V. All rights reserved.