CATALYSIS OF THE ELECTROCHEMICAL REDUCTION OF CARBON-DIOXIDE BY IRON(0) PORPHYRINS

Electrochemical conversion of carbon dioxide into organic chemicals has attracted attention for a long time. Direct electrochemical reduction at inert electrodes requires a very negative potential. In water it leads to formic acid whereas in aprotic solvents oxalate and carbon monoxide are obtained. Their relative yields are mainly a function of current density and CO//2 concentration, residual or purposely added water leading to formic acid also in this case. Various active metals used as electrode material or molecular catalysts based on transition metal complexes have been investigated, mostly in water, in an attempt to assist the electrochemical reduction and possibly obtain other products than formate. 13 Refs.