Advances in the Preparation Strategies and Structural Regulation for CeO2-containing Electrocatalysts Applied to the Anodes of Direct Alcohol Fuel Cells: A Comprehensive Review

Abstract

Direct alcohol fuel cells (DAFCs) are promising clean energy systems that directly transform the chemical energy of liquid alcohols into electricity. They have significant advantages with high energy densities and ease of fuel handling, and contribute to solving many problems that have been troubling people, such as the global energy crisis, environmental pollution, and global warming. However, common electrocatalysts such as Pt and Pd currently used in DAFCs’ anodes have many disadvantages, including low activity, poor stability, and susceptibility to poisoning, which seriously hamper the widespread commercialization of DAFCs. Cerium oxide (CeO₂) is an exceptionally promising cocatalyst material to overcome these limitations, with its low preparation cost, high stability, and outstanding redox performance stemming from the reversible Ce³⁺/Ce⁴⁺ conversion and exceptional oxygen storage capacity/oxygen release capacity. This review comprehensively summarizes recent progress in CeO₂-containing electrocatalysts applied to the anodes of DAFCs. The electrocatalytic mechanisms of the three main alcohol oxidation reactions (AORs) occurring on these composite materials are discussed in detail, namely methanol oxidation reaction (MOR), ethanol oxidation reaction (EOR), and ethylene glycol oxidation reaction (EGOR). The microstructure and key properties of CeO₂ crystals, which are crucial for their electrocatalytic performance, are deeply analyzed. Moreover, this paper examines the evolution of the preparation strategies and structural regulation aiming at optimizing the electrochemical performance of anodic CeO₂-containing electrocatalysts, and analyzes the challenges in terms of their preparation processes and structural regulation. Finally, this paper looks forward to the development trends and proposes research directions for next-generation CeO₂-containing electrocatalysts for the anodes of DAFCs, and emphasizes the significance of applying their unique properties to achieve efficient, durable, and cost-effective DAFCs.