Anion Effect in Electrocatalysts for Oxygen Evolution Reaction and Small Organic Molecule Oxidation

The growing global energy demand underscores the urgent need for efficient and stable electrocatalysts for clean energy conversion. The anion effect, which refers to the pivotal influence of anionic species in dynamically regulating the structure, electronic properties, and catalytic performance of electrocatalysts, is systematically summarized in this review for both the oxygen evolution reaction (OER) and the electrooxidation of small organic molecules. For the OER, we detail how anions undergo structural evolution and further enhance catalytic activity and stability through multiple mechanisms, including anion adsorption effect, anion leaching-induced metal oxidation and reconstruction, anion defect effect, anion intercalation effect, and electrostatic shielding effect. Furthermore, the discussion has also been extended to the electrooxidation of various organic molecules, such as 5-hydroxymethylfurfural (HMF), glycerol, methanol, and urea, where anion-mediated strategies enable the efficient synthesis of value-added chemicals. Finally, we conclude with a summary and outlook about the challenges and opportunities of anion effect in electrocatalysts for OER and electrooxidation of small organic molecules.