Rare earth metal-mediated electrode for glycerol electrooxidation: interfacial chemistry and reaction selectivity

Electrochemical glycerol oxidation (GOR) is a promising method for using biomass to produce value-added chemicals and efficiently generate hydrogen energy. However, the complex reaction mechanism, involving adsorption, surface reconstruction, C-H activation, dehydrogenation, C–C bond cleavage, and competing C 3 , C 2 , and C 1 pathways, makes it difficult to rationally design selective catalysts. Various reports have shown that rare-earth metals (REMs) offer opportunities to control both GOR activity and selectivity due to their unique electronic structures, high oxygen affinity, Lewis acidity, and involvement in oxygen-vacancy chemistry. Thus, this review examines whether REMs act as active sites or promoters via electronic redistribution, metal–oxygen interactions, lattice distortion, and surface reconstruction, informed by state-of-the-art characterization techniques such as operando spectroscopy, isotope labeling, and density functional theory. Finally, the structure-mechanism relationships and future approaches for the development of RE-engineered catalysts for the purpose of glycerol valorization have been discussed.