Controllable Electronic Transfer Tailoring d‐band Center via Cobalt–Oxygen‐Bridged Ru/Fe Dual‐sites for Boosted Oxygen Evolution

Abstract

AbstractRational tailoring of the electronic structure at the defined active center of reconstructed metal (oxy)hydroxides (MOOH) during oxygen evolution reaction (OER) remains a challenge. With the guidance of density functional theory (DFT), herein a dual‐site regulatory strategy is reported to tailor the d‐band center of the Co site in CoOOH via the controlled electronic transfer at the Ru─O─Co─O─Fe bonding structure. Through the bridged O2− site, electrons are vastly flowed from the t2g‐orbital of the Ru site to the low‐spin orbital of the Co site in the Ru–O–Co coordination and further transfer from the strong electron–electron repulsion of the Co site to the Fe site by the Co–O–Fe coordination, which balancing the electronic configuration of Co sites to weaken the over‐strong adsorption energy barrier of OH* and O*, respectively. Benefiting from the highly active of the Co site, the constructed (Ru2Fe2Co6)OOH provide an extremely low overpotential of 248 mV and a Tafel slope of 32.5 mV dec−1 at 10 mA cm−2 accompanied by long durability in alkaline OER, far superior over the pristine and Co–O–Fe bridged CoOOH catalysts. This work provides guidance for the rational design and in‐depth analysis of the optimized role of metal dual‐sites.