Abstract An ever-increasing energy demand has stimulated intense research into electrochemical technologies for both energy storage and conversion such as unitized regenerative fuel cells (URFCs). Due to its high efficiency, low cost, and low environmental impact, the URFC, which combines a polymer electrolyte membrane fuel cell (PEMFC) with a polymer electrolyte water electrolyzer (PEWE), has been regarded as an important energy technology that can offer new opportunities to not only further reduce investment costs but also to open doors to the mass production of domestic applications. Despite this, URFCs still have to be further improved and optimized to reach a level of maturity of both fuel cells and electrolyzers in terms of energy efficiency and long-term performance. Currently, the major challenge of URFC technology has been the insufficient performance of the bifunctional electrocatalyst. Based on the most recent research trends and progresses of bifunctional oxygen catalyst materials, this review will provide a systematic introduction and a comprehensive assessment of various bifunctional oxygen catalysts; their science and technology, including material selection, synthesis, and characterization, as well as their applications in URFCs. This review aims to correlate the physicochemical characteristics of URFCs with the catalytic activity/stability of these materials.

中文翻译：

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单元化再生燃料电池 (URFC) 氧电极双功能电催化剂开发的最新进展

摘要 不断增长的能源需求刺激了对用于能量存储和转换的电化学技术的深入研究，例如单元化再生燃料电池 (URFC)。由于其高效、低成本和低环境影响，将聚合物电解质膜燃料电池 (PEMFC) 与聚合物电解质水电解槽 (PEWE) 相结合的 URFC 已被视为一种重要的能源技术，可以提供新的能源。不仅可以进一步降低投资成本，还可以为国内应用的大规模生产打开大门。尽管如此，URFCs 仍然需要进一步改进和优化，以在能源效率和长期性能方面达到燃料电池和电解槽的成熟水平。现在，URFC 技术的主要挑战是双功能电催化剂的性能不足。本综述将基于双功能氧催化剂材料的最新研究趋势和进展，对各种双功能氧催化剂进行系统介绍和综合评价；他们的科学和技术，包括材料选择、合成和表征，以及它们在 URFC 中的应用。本综述旨在将 URFC 的理化特性与这些材料的催化活性/稳定性相关联。本综述将对各种双功能氧催化剂进行系统介绍和综合评估；他们的科学和技术，包括材料选择、合成和表征，以及它们在 URFC 中的应用。本综述旨在将 URFC 的理化特性与这些材料的催化活性/稳定性相关联。本综述将对各种双功能氧催化剂进行系统介绍和综合评估；他们的科学和技术，包括材料选择、合成和表征，以及它们在 URFC 中的应用。本综述旨在将 URFC 的理化特性与这些材料的催化活性/稳定性相关联。