Effect of metal-substitution on the redox behaviors of mono-transition metal-substituted Wells–Dawson tungstoarsenates

• KnAs2W17M1O62 (M = W, Mo, V, and Nb) Wells–Dawson tungstoarsenates were prepared.
• Reduction potentials were measured by an electrochemical method.
• Absorption edge energies were determined by UV–visible spectroscopy.
• Oxidative dehydrogenation of benzylamine was conducted.
• Yield for dibenzylimine increased with increasing redox properties.

Mono-transition metal (Mo, V, and Nb)-substituted Wells–Dawson tungstoarsenates were investigated to elucidate the effect of metal-substitution on their redox behaviors. In the electrochemical analysis, an additional redox transition was observed for molybdenum- and vanadium-substituted tungstoarsenates, while a negatively shifted redox transition was observed for niobium-substituted tungstoarsenate. First electron reduction potential of the catalysts showed the consistent trend with UV–visible absorption edge energy of the catalysts. Oxidative dehydrogenation of benzylamine to dibenzylimine was carried out as a model reaction to probe oxidation catalysis. Yield for dibenzylimine increased with increasing first electron reduction potential and with decreasing UV–visible absorption edge energy.

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