Reduction of CO<inf>2</inf> by nickel (II) macrocycle catalyst at HMDE

With the aim of finding a suitable electrocatalyst for the efficient reduction of carbon dioxide, the electrochemistry of nickel (II) complex of 1,3,6,9,11,14-hexaazatricyclo [12.2.1.1] octadecane was studied using cyclic voltammetry (CV) and controlled-potential electrolysis (CPE) techniques in the presence and absence of CO2 in 100% H2O, CH3CN-H2O mixtures (20-100%) and DMF-H2O (70-100%) mixtures. The efficiency of this process is determined using the coulometry technique. CO is the major product in the gaseous phase and HCOOH the sole product formed in the solution phase.