The Synergistic Effect of Oxygen Vacancy and Carbon Interface Engineering in Hollow Cerium Oxide to Achieve Enhanced Oxygen Reduction Performance

Vacancy defect and interface engineering are confirmed to be beneficial to different electrocatalytic reactions. However, the combination of vacancy and interfacial effects to improve the oxygen reduction reaction performance of CeO2-based electrocatalysts has not been reported yet, and its internal mechanism remains to be further studied. Herein, a N-doped carbon-coated CeO2 hollow structure with massive oxygen vacancy (Vo-CeO2-NC) has been developed via a facile strategy. The Vo-CeO2-NC catalyst exhibits high oxygen reduction reaction performance, with an excellent half-wave potential (0.88 V vs RHE) and onset potential (0.95 V vs RHE). Combining with density functional theory calculations, the catalytic results indicate that the synergistic effect of oxygen vacancies and the N-doped carbon interface layer could promote the conductivity of CeO2 and provide a strong interfacial interaction and significantly promote the catalyst oxygen reduction reaction performance. In addition, a zinc-air battery assembled by Vo-CeO2-NC exhibits a significantly enhanced performance with a power density of 145.1 mW cm–2, better than that of the commercial Pt/C catalyst (121.8 mW cm–2). This work not only combines oxygen vacancy and the carbon interface layer to enhance the oxygen reduction reaction activity of the catalyst for the first time but also sheds light on the in-depth mechanism of vacancy-interface interactions.