Electrochemical Reduction of Carbon Dioxide Using Iron-Sulfur Clusters as Catalyst Precursors

Article abstract of DOI:10.1246/bcsj.59.809

The potential-current relationships of DMF solutions of a series of iron-sulfur compounds have revealed that in the presence of clusters ^2- (R=PhCH2 or Bu^t) and ^3- (M=Mo or W) the electroreduction of CO2 proceeds at the potential shifted by about 0.7 and 0.5 V, respectively, to the positive direction compared to the potential at which CO2 is reduced without any catalyst.When controlled potential electrolysis of a DMF solution containing ^2- was carried out under CO2 at -2.0 V vs.SCE, phenylacetate and formate were formed as the products resulting from CO2 reduction.The cubane structure of this cluster collapsed rapidly under these conditions.However, when excess amount of PhCH2SH was added to the catholyte, the cluster structure was preserved during a relatively long period of electrolysis, and the yield of phenylacetate increased but that of formate decreased compared with the reaction in the absence of free PhCH2SH.