Based Nafion gas sensor utilizing Pt-MOx (MOx = SnO2, In2O3, CuO) sensing electrode for CH3OH detection at room temperature in FCVs

The development of high-performance gas sensors for detecting trace amount of CH3OH is an essential and a challenging task for safety using fuel cell vehicles (FCVs). In this work, the metal oxides (SnO2, In2O3, CuO) are employed as the catalyst carrier materials in fuel cell type sensors for the first time to replace traditional carbon, with which the Pt/MOx based fuel cell type sensors are fabricated. Among them, Pt/SnO2 based sensor displays the lowest detection limit because SnO2 carrier can not only support Pt particles but also provide an appropriate number of electrons for Pt, which is beneficial to reduce the adsorption strength of the intermediates and then improves the catalytic ability. The detection limit is as low as 0.5 ppm, the lowest of the various types of CH3OH sensors that work at room temperature. Moreover, the Pt/SnO2 based fuel cell type sensor displays the characters of high selectivity, good repeatability and robust moisture resistance. To the best of our knowledge, this is the first report employing MOx as the catalyst carrier materials in fuel cell type sensors.