All-inorganic and earth-abundant bi-/trimetallic hydr(oxy)oxides are widely used as oxygen evolution electrocatalysts owing to their remarkable performance. However, their atomically precise structures remain undefined, complicating their optimization and limiting the understanding of their enhanced performance. Here, the underlying structure-property correlation is explored by using a well-defined cobalt-phosphate polyoxometalate cluster [{Co4(OH)3(PO4)}4(SiW9O34)4]32− (1), which may serve as a molecular model of multimetal hydr(oxy)oxides. The catalytic activity is enhanced upon replacing Co by Fe in 1, resulting in a reduced overpotential (385 mV) for oxygen evolution (by 66 mV) compared to that of the parent 1 at 10 mA cm−2 in an acidic medium; this overpotential is comparable to that for the IrO2 catalyst. These abundant-metal-based polyoxometalates exhibit high stability, with no evidence of degradation even after 24 h of operation.

中文翻译：

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铁取代的磷酸钴多金属氧酸盐作为酸性介质中增强的析氧催化剂

全无机和地球上含量丰富的双/三金属羟基（氧）氧化物由于其卓越的性能而被广泛用作析氧电催化剂。然而，它们的原子精确结构仍未定义，这使它们的优化复杂化并限制了对其增强性能的理解。在这里，通过使用明确定义的磷酸钴多金属氧酸盐簇 [{Co4(OH)3(PO4)}4(SiW9O34)4]32− (1) 探索了潜在的结构 - 性质相关性，它可以作为分子多金属羟基（氧）氧化物模型。在 1 中用 Fe 代替 Co 后催化活性增强，导致与母体 1 在酸性介质中 10 mA cm-2 相比，析氧过电位（385 mV）降低（66 mV）；该超电势与 IrO2 催化剂的超电势相当。