Ethanol electro-oxidation on a carbon-supported Pt–Mo electrocatalyst: a study by pinhole on-line differential electrochemical mass spectrometry

The ethanol oxidation reaction (EOR) was studied on carbon-supported Pt and Pt-Mo electrocatalysts prepared by the formic acid reduction method following heat-treatment. The catalysts were physically characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electrocatalytic activity of the Pt/C and Pt-Mo/C electrocatalysts for the EOR was investigated by potentiostatic and potentiodynamic measurements with pinhole on-line differential electrochemical mass spectrometry (PODEMS). The results show that the Pt-Mo/C electrocatalyst compared with Pt/C has higher ethanol oxidation efficiency and, acetaldehyde and acetic acid are majority products during the EOR under the given conditions. The CO₂ current efficiencies (CCEs) on the Pt/C and Pt-Mo/C catalysts are 6.9% and 8.8% after calibration of the mass to charge signal <i>m</i>/<i>z</i> = 44, respectively, which reveals that the co-metal molybdenum produces more CO₂ for ethanol electrooxidation and promotes the performance of the Pt-based anode catalyst.