Cerium-Incorporated Carbon Catalysts Prepared via a Biomass–Zeolitic Imidazolate Framework Hybrid Strategy for Efficient Oxygen Reduction

Cerium (Ce)-incorporated carbon catalysts, particularly Ce catalysts with Ce–N active sites supported by carbon, have emerged as promising alternatives to noble metal-based catalysts for electrocatalyzing the oxygen reduction reaction (ORR). However, most carbon-supported Ce catalysts featuring Ce–N active sites remain at the proof-of-concept stage, with challenges in synthesis, including the lack of facile synthesis strategies compatible with scalable production. Herein, we present a simple and direct method for preparing Ce-incorporated carbon catalysts by carbonizing a mixture of vital wheat gluten, a type of renewable biomass, and Ce-doped zeolitic imidazolate framework-8. The optimized catalyst exhibits a half-wave potential of 0.82 V and good stability in an alkaline electrolyte. Structural and electrochemical analyses indicate that both CeO2 nanoparticles and Ce–N moieties exist in the obtained catalyst, while the Ce–N moieties are responsible for its efficient ORR activity. A zinc-air battery based on this catalyst delivers a higher peak power density and better durability (90 h) than one based on Pt/C. These results should pave the way for the biomass-assisted synthesis of Ce-incorporated carbon catalysts for ORR, providing a foundation for future scalable production.