Mo-V-O Based Electrocatalysts for Low Temperature Alcohol Oxidation

There is a growing interest in alcohol oxidation electrochemistry due to its role in renewable energy technologies. The goal of this work was to develop active non- precious metal electrocatalysts based on the Mo-V-(M)-O (M is Nb, Te) lattice. Selective gaseous alkane oxidation had been previously observed on these catalysts at elevated temperatures above 300 °C. In this study, the activity of the catalysts at lower temperatures, 25-60 °C, was investigated. Hydrothermal conditions were used to synthesize the Mo-V-(M)-O mixed oxides. Physical characterization of the catalysts were obtained by powder X-ray diffraction (XRD), scanning electron micrography (SEM) equipped with energy dispersive X-ray (EDX), transmission electron micrography (TEM), and X-ray photoelectron spectroscopy (XPS). The catalytic activity for the oxidation of cyclohexanol was studied electrochemically. Chronoamperometric studies were used to evaluate the long-term performance of the catalysts. The onset of alcohol oxidative current was observed between 0.2 and 0.6 V versus Ag/AgCl. Gas chromatography-mass spectrometry analysis was used to determine the nature of the oxidative products. The mild oxidation products, cyclohexanone and cyclohexene, were observed after oxidation at 60 °C. The catalytic activity increased in the order Mo-V-O < Mo-V-Te-O < Mo-V-Te-Nb-O. Mo-V-(Te,Nb)-O based electrocatalysts efficiently catalyzed the oxidation of alcohols at low temperatures.