A fast metal–metal bonded water oxidation catalyst

[Display omitted] •Diruthenium tetraacetate is a fast homogeneous water oxidation catalyst (WOC).•Its limiting rate for oxygen evolution is 77s−1, second fastest reported in Ru chemistry.•It is the first metal–metal bonded WOC.•This catalyst exhibits high activity in a wide pH range.•The mechanism operates through a single-site and explains the fast kinetics. The metal–metal bonded diruthenium (II,II) tetraacetate compound, [Ru2(μ-O2CCH3)4], is a water oxidation catalyst (WOC) that exhibits oxygen evolution rates as high as 77s−1 at ambient conditions, exhibiting comparable catalytic activity over a wide pH range (1