Surface‐Adsorbed Carboxylate Ligands on Layered Double Hydroxides/Metal–Organic Frameworks Promote the Electrocatalytic Oxygen Evolution Reaction

Abstract Metal–organic frameworks (MOFs) with carboxylate ligands as co‐catalysts are very efficient for the oxygen evolution reaction (OER). However, the role of local adsorbed carboxylate ligands around the in‐situ‐transformed metal (oxy)hydroxides during OER is often overlooked. We reveal the extraordinary role and mechanism of surface‐adsorbed carboxylate ligands on bi/trimetallic layered double hydroxides (LDHs)/MOFs for OER electrocatalytic activity enhancement. The results of X‐ray photoelectron spectroscopy (XPS), synchrotron X‐ray absorption spectroscopy, and density functional theory (DFT) calculations show that the carboxylic groups around metal (oxy)hydroxides can efficiently induce interfacial electron redistribution, facilitate an abundant high‐valence state of nickel species with a partially distorted octahedral structure, and optimize the d‐band center together with the beneficial Gibbs free energy of the intermediate. Furthermore, the results of in situ Raman and FTIR spectra reveal that the surface‐adsorbed carboxylate ligands as Lewis base can promote sluggish OER kinetics by accelerating proton transfer and facilitating adsorption, activation, and dissociation of hydroxyl ions (OH − ).