ChemInform Abstract: Carbon Dioxide Reduction Mediated by Electropolymerized Electrodes of a Nickel Tetraazaannulene Complex, Ni[Me4Bzo2[14]tetraeneN4].

ChemInform Abstract

Cyclic voltammetric measurements and investigations using controlled potential electrolysis show that CO₂ can be reduced electrochemically at - 1.85 V at an electrode containing a thin polymeric film of the Ni complex of (I). The title complex catalyzes the reduction and serves as electron mediator between the electrode surface and coordinated CO₂ to Ni(II) sites within the film. The only observed product upon reduction is the formate ion. CO₂ is not reduced using a bare glassy carbon electrode, either in the presence or absence of a proton source. In the absence of CO₂ the Ni complex film exhibits surface waves in which the Ni(′II)/Ni(I) redox couple occurs at ca. - 1.82 V. The presence of a proton source promotes electron transfer to CO₂, which results in an increase in CO₂ reduction.