Abstract
In the present work, we made comparative studies of the electrocatalytic performance toward proton reduction of Cu(II), Fe(III) and Co(III) complexes with pyridoxal-thiosemicarbazone (PLTSC) ligand. Knowing that the direct reduction of CH3COOH on the surface of vitreous carbon electrode occurs at Ep = -1.8 V vs Ag/AgCl in [Bu4N][BF4]-DMF solution, the presence of Fe(III), Cu(II) or Co(III) complex significantly shifts the peak potential to the more positive values, Ep = -1.42, -1.48, and -1.63 V, respectively vs Ag/AgCl. In the presence of acid, the peak current values for Fe(III), Cu( II), and Co(III) complexes was increased of about 2.6, 7.2 and 2.2 times, respectively compared to the acid-free solution. This indicates the superiority of the Cu(II) complex for hydrogen production compared to Fe( III) and Co(III) complexes.