From Electronic Structure to Catalytic Function: Rare Earth-Driven Strategies for CO₂ Electroreduction

Electrochemical carbon dioxide reduction reaction (CO₂RR) is a promising approach to mitigate carbon emissions while producing value-added fuels and chemicals. However, conventional transition-metal catalysts suffer from limited selectivity, high overpotentials, and poor durability. Rare-earth elements, with their unique 4f orbital configurations, variable oxidation states, and strong oxophilicity, offer distinct opportunities to overcome these limitations. This review systematically summarizes recent advances in rare-earth-based electrocatalysts, including single-atom catalysts (SACs), alloys, and oxides, highlighting their ability to tailor local coordination environments, stabilize oxygenated intermediates, and facilitate multi-electron transfer pathways. Rare-earth-based SACs leverage atomic dispersion to modulate electronic structures and suppress competing hydrogen evolution, while rare-earth-containing alloys introduce synergistic effects that disrupt conventional scaling relationships, enhancing selectivity toward desired products. Furthermore, rare-earth oxides and mixed phases offer active oxygen vacancies and redox flexibility, thereby promoting CO₂ activation and enhancing catalyst stability. Collectively, these strategies significantly improve activity, selectivity, and durability in CO₂RR. Despite these advances, challenges remain regarding atomic dispersion stability, conductivity, and product selectivity toward multi-carbon species. Future research should focus on rational design guided by operando characterization, defect engineering, and machine-learning-assisted discovery to realize rare-earth-based electrocatalysts for industrially relevant, carbon-neutral CO₂ conversion.