Electrochemical reduction of oxygen with iron phthalocyanine in neutral media

Recent interest in electricity production using microbial fuel cells makes it important to better understand O2 reduction in neutral solutions with non-precious metal catalysts. Higher O2 reduction activity was obtained using iron phthalocyanine supported on Ketjen black carbon (FePc-KJB) than with a platinum catalyst in neutral pH. At low overpotentials, a Tafel slope close to -0.06 V/dec in both acid and neutral pH suggested that the mechanism of O2 reduction on FePc is not changed with the change of pH, and the reaction is mainly controlled by Fe/Fe redox couple. This behaviour gives us new insight into catalysis using FePc, and further supports the use of FePc as a promising catalyst for the oxygen reduction applications in neutral media.