Thermal Properties of the Stationary Current in Mesoporous Pt/TiO₂ Structures in an Oxyhydrogen Atmosphere

We report on the effect of temperature on the electric current induced in the mesoporous Pt/TiO2 structure by the room temperature surface chemical reaction of hydrogen and oxygen,13,14 which helps to unveil the physical origin of this current and the related electromotive force (chemi-EMF). We found that the temperature dependence of this reaction current has a clear multipeak structure, suggesting that at least two distinct processes contribute to the current generation. We suggest that the output current represents the interplay of both chemical and electrical processes, evidenced by the metastability of the room temperature reaction and by matching one of the current peaks with a water desorption peak for TiO2.