Ligand Effects and Their Impact on Electrocatalytic Processes Exemplified with the Oxygen Evolution Reaction (OER) on RuO₂(110)

Abstract

Abstract By using the ab initio atomistic thermodynamics approach guided by a DFT‐derived volcano curve, we demonstrate that the thermodynamic part of the reaction barrier to the oxygen evolution reaction (OER) over RuO 2 (110) can be significantly reduced when moderately lowering the free adsorption energy of oxygen to the catalytically active Ru center (Ru cus ). With the selective replacement of metal sites in the second coordination shell of Ru cus , the free oxygen adsorption energy is reduced by about 0.8 and 1.0 eV for Cr and Ir, respectively. The weakening of Ru cus and oxygen‐on‐top (Ru cus O ot ) bonding results in a substantial decrease in the thermodynamic part of the reaction barrier (Gibbs free‐energy loss) by 180 meV for Cr and 150 meV for Ir. The presented strategy is motivated by homogeneous metal catalysis where dedicated modifications of the ligands are able to tune the catalytic performance of the active metal center.