Molecular Transition Metal Oxide Electrocatalysts for the Reversible Carbon Dioxide–Carbon Monoxide Transformation
Dima Azaiza‐Dabbah, Charlotte Vogt, Fei Wang, Albert Masip‐Sánchez, Coen de Graaf, Josep M. Poblet, Eynat Haviv, Ronny Neumann
Abstract
Abstract Carbon monoxide dehydrogenase (CODH) enzymes are active for the reversible CO oxidation–CO 2 reduction reaction and are of interest in the context of CO 2 abatement and carbon‐neutral solar fuels. Bioinspired by the active‐site composition of the CODHs, polyoxometalates triply substituted with first‐row transition metals were modularly synthesized. The polyanions, in short, {SiM 3 W 9 } and {SiM′ 2 M′′W 9 }, M, M′, M′′=Cu II , Ni II , Fe III are shown to be electrocatalysts for reversible CO oxidation–CO 2 reduction. A catalytic Tafel plot showed that {SiCu 3 W 9 } was the most reactive for CO 2 reduction, and electrolysis reactions yielded significant amounts of CO with 98 % faradaic efficiency. In contrast, Fe–Ni compounds such as {SiFeNi 2 W 9 } preferably catalyzed the oxidation of CO to CO 2 similar to what is observed for the [NiFe]‐CODH enzyme. Compositional control of the heterometal complexes, now and in the future, leads to control of reactivity and selectivity for CO 2 electrocatalytic reduction.