Investigation of electrocatalytic activity of NiTPPBr6 on the graphite electrode for oxidation of methanol, ethanol, 1-propanol and 2-propanol

Abstract

Due to the importance of producing clean energy through systems such as alcoholic fuel cell, methanol, ethanol, 1-propanol, and 2-propanol, these alcohols were oxidized at the modified graphite electrode by NiTPPBr6 / NiTPPBr8 as a clean electrocatalyst in an alkaline media. This process investigated by various techniques such as cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS), in all cases showed Cottrell type behavior with the diffusion of coefficients of 2.04 × 10[Formula: see text], 1.3 × 10[Formula: see text] 8.3 × 10[Formula: see text] cm[Formula: see text] s[Formula: see text] for the corresponding alcohols respectively. Likewise, the catalytic rate constant for methanol oxidation was found to be 2.9 × 108 cm3mol[Formula: see text] s[Formula: see text] through chronoamperometric measurements. Interestingly, the order in activity for oxidation of the alcohols introduced with the electrocatalyst was: 2-propanol [Formula: see text] 1-propanol [Formula: see text] ethanol [Formula: see text] methanol and was unlike previous studies in which the oxidation current was reduced by increasing the number of carbon atoms from methanol to propanol.