High-throughput chainmail catalyst FeCo@C nanoparticle for oxygen evolution reaction

Oxygen evolution reaction (OER) is a key part of water electrolysis for hydrogen production . Non-noble-metal catalysts with high activity, stability, but low cost are prerequisites for practical application. In this work, sucrose char was synthesized and then chainmail catalysts were produced by in situ growth method, defined as M@C (M = Fe, Co and FeCo). FeCo@C showed great OER performance in both catalytic activity and durability tests. The overpotentials were 302 mV (at the current density of 10 mA cm −2 ) and 423 mV (at 50 mA cm −2 ), with a lowest Tafel slope of 75 mV dec −1 . The electrochemical surface area of catalysts were also analyzed by calculating the capacitance of the double layer to further investigate the catalytic activity. Furthermore, FeCo@C showed superior stability after 30 h test or 10,000 cycles of cyclic voltammetry . Theoretical calculation based on density functional theory (DFT) demonstrated that the overpotential of OER was determined by the Gibbs free energies of reaction intermediates HO∗, O∗ and HOO∗. The adsorption of HO∗ radicals onto the FeCo@C was weaker than Fe@C, which was favorable for reducing the overpotential, as the rate-determining step of the OER process over these catalysts was that HO∗ dehydrogenated to form O∗.