Recovery of High Purity Chlorine by Cu‐Doped Fe2O3 in Nitrogen Containing Carbon Matrix: A Bifunctional Electrocatalyst for HCl Electrolysis

Abstract

AbstractAn environmentally benign approach towards synthesis of a non‐noble metal and/or metal oxide doped incorporated in nitrogen containing carbon matrix (Cu−Fe2O3/NC) is premeditated in this study. In‐situ incorporation of Cu, Fe2O3 as well as nitrogen into the carbon matrix using a single gel precursor simplified the synthetic route and divulged bifunctional activity assisting chlorine evolution at anode and oxygen reduction reaction at cathodic counterpart during HCl electrolysis. As a result of synergy between Cu and Fe2O3 in N‐ doped carbon matrix, enhanced activity and stability is stimulated. Catalyst optimization was executed by varying the weight percentage of metal reactants added during precursor synthesis (2, 5 and 10 wt. %), which rendered different composition of Cu, Fe2O3 and N in the composite with flake‐like morphology at same thermal treatment conditions. Electrochemical studies were performed in 0.4 M HCl analogous to industrial waste HCl, to investigate the bifunctional activity of catalyst where Cu−Fe2O3 (5 %)/NC came out to be the most active and exhibited long term stability for 24 hours at onset potential of chlorine evolution. It offered a higher current density of 92.1 mA cm−2 at 1.7 V vs. RHE during chlorine evolution and comparable activity to that of benchmark noble metal based catalyst along with more positive onset potential and high diffusion limiting current density of 0.78 V vs. RHE and 6 mA cm−2 during oxygen reduction respectively.