DFT characterization on the effect of redox-inactive cation Ca2+ on water oxidation by CoII-based cuboidal catalyst

Publication date: Available online 2 February 2019Source: Computational and Theoretical ChemistryAuthor(s): Xiao-Fang Su, Bo Zhu, Li Liu, Li-Kai Yan, Zhong-Min SuAbstractThe activity of the biomimetic CoII-based cuboidal water oxidation catalyst (WOC) [CoII4(hmp)4(μ-OAc)2(μ2-OAc)2(H2O)] ([CoII4O4]) and its Ca2+-substitute [CoII3CaO4] were theoretically investigated to evaluate the effect of redox-inactive Ca2+ on water oxidation by CoII-based cuboidal catalyst. Compared with [CoII4O4], the smaller redox potential of [CoII3CaO4] results in the more efficient oxidation-equivalents accumulation for water oxidation. By contrast, the water oxidation by [CoII3CaO4] is identified to be more thermodynamically superior than that for [CoII4O4]. The energy barrier of key O–O bond formation step in water oxidation by [CoII3CaO4] is 22.0 kcal/mol and lower than that found for [CoII4O4] (25.0 kcal/mol).Graphical abstract

Source: Computational and Theoretical Chemistry - February 3, 2019 Category: Chemistry Source Type: research