Review of recent research work on CeO2-based electrocatalysts in liquid-phase electrolytes

The urgent need of renewable energy and environmental issues drive many studies on electrocatalytic materials and stimulate abundant investigation to improve the catalytic activity of these electrocatalysts. Among numerous inorganic materials, CeO2-based electrocatalysts with flexible transform between Ce3+ and Ce4+ states and the abundant oxygen vacancies become one of the most promising candidates. This review summarizes the recent development in the synthetic strategy of CeO2-based nanomaterials and their applications in several representative electrochemical reactions, such as hydrogen evolution reaction, oxygen evolution reaction, hydrogen oxidation reaction, organic molecular oxidation reaction, oxygen reduction reaction, N2 reduction reaction and CO2 reduction reaction in liquid-phase electrolyte. By virtue of advanced characterization techniques and computational studies based on density functional theory (DFT), the detailed effects of CeO2 on these reactions and the specific mechanism to improve the catalytic efficiency are discussed and analyzed as well. In parallel, some strategies and procedure are proposed for the design and synthesis of CeO2-based electrocatalysts to achieve better catalytic performance. Finally, several challenges and perspectives in this emerging research area are proposed. To some extent, we believe that this review is also helpful for designing other high catalytic performance materials toward energy conversion and storage.