Two or four? The development of highly efficient inexpensive earth-abundant metal-based oxygen electrocatalysts that will replace noble metal-based ones requires an understanding of the catalytic mechanisms of the two-electron/two-proton and four-electron/four-proton reductions of dioxygen, which are important processes for fuel cell technologies and are typically catalyzed by costly Pt-based electrocatalysts. This Review is focused on the factors that control these reductions, catalyzed by earth-abundant metal complexes.

中文翻译：

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富含地球的金属配合物催化双电子对四电子还原双氧的机理

两四个？要开发出能替代贵金属的高效廉价廉价的富含地球的金属基氧电催化剂，需要了解双氧的两个电子/两个质子和四个电子/四个质子还原的催化机理，这些是燃料电池技术的重要过程，通常由昂贵的基于Pt的电催化剂催化。这篇综述的重点是由地球上丰富的金属络合物催化的控制这些还原的因素。