A tungsten-mediated closed cycle of reactivity for the reduction of CO2 to CO

Abstract

The recycling of CO₂ by reduction to CO is an important objective in the context of renewable carbon feedstock chemicals. A tungsten-mediated reduction of CO₂ to CO reported by Mayer and coworkers has been re-examined, and it is shown that a series of four well-defined stoichiometric steps can be executed which form a closed cycle and sum as CO₂ + 2H⁺ + 2e⁻ → CO + H₂O. Energetic parameters of this system are probed by cyclic voltammetry, by calculations of gas-phase reaction enthalpies for each of the four steps, and by calculation of the WO bond dissociation energy for the tungsten species that results from oxidation addition of CO₂.