Viologen containing nickel complexes were synthesized and their electrocatalytic activities towards carbon dioxide conversion were examined. They could convert carbon dioxide at -0.6 ~ -0.9 V region and the major product was found to be carbon monoxide. Electrolysis of Ni cyclam viologen in CO2 saturated 0.1 M phosphate buffer at pH 7 showed current efficiency of more than 60%.
Figure 1. Cyclic voltammograms of Ni cyclam viologen under CO2 (solid line) and Ar (dotted line) at scan rate of 5mV/s.