Abstract Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are two critical processes for metal-air batteries (MABs) that afford large energy capacity and high power density. However, both reactions suffer from sluggish kinetics. The availability of efficient electrocatalysts that could conquer activation energy barriers and accelerate reaction rates is crucial to tackling this issue. The noble metal-based electrocatalysts (e.g., Pt/C and Ru/IrO2) cannot meet the requirement for large-scale applications due to their scarce abundance, high cost, and insufficient stability. Transition metal-based materials can be a sustainable and promising candidate to replace the noble metal-based electrocatalysts for this purpose. This review intends to review the most recent, high performance, and sustainable strategies on tuning the catalytic activity of the transition metal-based materials toward ORR and OER. We also propose perspectives on remaining challenges and future research directions of transition metal-based bifunctional electrocatalysts toward practical applications. These fundamental design principles and strategies are crucial to guide and accelerate the design of the ideal catalysts and make possible the practical applications of MABs.

中文翻译：

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用于氧还原和析出反应的可持续过渡金属基双功能电催化剂的合理设计

摘要 氧还原反应（ORR）和析氧反应（OER）是金属-空气电池（MAB）的两个关键过程，具有大能量容量和高功率密度。然而，这两种反应的动力学都很缓慢。可以克服活化能障碍并加快反应速率的高效电催化剂的可用性对于解决这个问题至关重要。贵金属基电催化剂（如Pt/C和Ru/IrO2）由于其丰度稀少、成本高、稳定性不足等问题，无法满足大规模应用的需求。为此目的，过渡金属基材料可以成为替代贵金属基电催化剂的可持续且有前景的候选材料。本次审查旨在审查最新的、高性能的、以及调整过渡金属基材料对 ORR 和 OER 的催化活性的可持续策略。我们还提出了关于过渡金属基双功能电催化剂在实际应用中的剩余挑战和未来研究方向的观点。这些基本设计原则和策略对于指导和加速理想催化剂的设计以及使 MAB 的实际应用成为可能至关重要。