Soluble Gd 6 Cu 24 clusters: effective molecular electrocatalysts for water oxidation.

The water oxidation half reaction in water splitting for hydrogen production is extremely rate-limiting. This study reports the synthesis of two heterometallic clusters (Gd ₆ Cu ₂₄ -IM and Gd ₆ Cu ₂₄ -AC) for application as efficient water oxidation catalysts. Interestingly, the maximum turnover frequency of Gd ₆ Cu ₂₄ -IM in an NaAc solution of a weak acid (pH 6) was 319 s ^-1 . The trimetallic catalytic site, H ₂ O-Gd ^III Cu ^II ₂ -H ₂ O, underwent two consecutive two-electron two-proton coupled transfer processes to form high-valent Gd ^III -O-O-Cu ^III ₂ intermediates. Furthermore, the O-O bond was formed via intramolecular interactions between the Cu ^III and Gd ^III centers. The results of this study revealed that synergistic catalytic water oxidation between polymetallic sites can be an effective strategy for regulating O-O bond formation.
Competing Interests: The authors declare no competing financial interest.
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