Low-temperature hydrocarbon combustion over proton conductor/metal-mixed catalysts

摘要

Catalytic combustion of hydrocarbons is a highly active field of research, particularly in relation to the reduction of pollutant emissions from automobiles. In this study, we report on hydrocarbon oxidation at the internal interfaces of a mixed catalyst consisting of Sn_(0.9)In _(0.1)P_2O_7 and Pt powders. In a gaseous mixture of propane, H_2O, and O_2, the H_2O dissociates into protons, electrons and active oxygen species at anodic interface sites, leading to oxidation of the hydrocarbon to CO_2. On the other hand, O _2 reacts with protons and electrons to form H_2O at cathodic interface sites. As a consequence, local electrochemical cells are formed at the interfaces, and undergo self-discharge. It was shown that the mixed catalyst had a high turnover frequency for Pt, yielding high catalytic activity for Pt contents of as low as 0.1 wt% and an initiation temperature for hydrocarbon oxidation of 150 °C.