Influence of solvent on the electrocatalytic behaviour of nickel(II) macrocyclic complex of 1,3,6,9,11,14-hexaazacyclohexadecane towards the reduction of carbon dioxide at HMDE

Cyclic voltammetry (CV), control potential electrolysis (CPE), gas chromatography (GC) and photometric techniques have been used to investigate the electrochemical reduction of carbon dioxide using the title complex as catalyst at hanging mercury drop electrode (HMDE) in aqueous and aqueous mixtures of organic solvents. The products were found to be carbon monoxide and hydrogen in gaseous phase and trace amounts of formic acid in solution phase. The product selectivity is determined by the protophilic or protophobic nature of the solvent.