The oxygen reduction reaction (ORR) is an electrochemical process of the utmost importance in energy conversion and storage, corrosion and chemical technologies. The ORR plays a major role in biological processes (such as respiratory biochemical chain reactions) and is being incorporated into numerous bioelectrochemical devices and systems, such as microbial and enzymatic fuel cells, microbiosynthesis processes, water desalination and purification technologies and biosensing. Researchers from various backgrounds have come together to address the specifics of the ORR in close-to-neutral environments in light of their possible integration with bioprocesses. Understanding the ORR mechanism in this pH region is complex, as it involves biotic (living systems or components derived thereof) and abiotic (often inorganic materials or composite) catalysts. This review offers a summary of catalyst-class-dependent ORR mechanisms and pathways with the corresponding limitations relevant to their practical use in bioelectrocatalytic systems. We also analyse the technological challenges often caused by the use of oxygen depolarization as the main driving force in practical applications.

氧还原反应 (ORR) 是一种在能量转换和储存、腐蚀和化学技术中极为重要的电化学过程。ORR 在生物过程（例如呼吸生化链式反应）中发挥着重要作用，并且正在被纳入许多生物电化学设备和系统中，例如微生物和酶燃料电池、微生物合成过程、水淡化和净化技术以及生物传感。鉴于 ORR 可能与生物过程相结合，来自不同背景的研究人员齐聚一堂，解决接近中性环境中 ORR 的具体问题。了解这个 pH 区域的 ORR 机制是复杂的，因为它涉及生物（生命系统或其衍生成分）和非生物（通常是无机材料或复合材料）催化剂。本综述总结了依赖于催化剂类别的 ORR 机制和途径，以及与它们在生物电催化系统中的实际应用相关的相应限制。我们还分析了在实际应用中使用氧去极化作为主要驱动力经常引起的技术挑战。