Theoretical Investigation of Catalytic Water Splitting by the Arene-Anchored Actinide Complexes

Actinide complexes, which could enable the electrocatalytic H2O reduction, are not well documented because of the fact that actinide-containing catalysts are precluded by extremely stable actinyl species. Herein, by using relativistic density functional theory calculations, the arene-anchored trivalent actinide complexes (Me,MeArO)(3)ArAn (marked as [AnL]) with desirable electron transport between metal and ligand arene are investigated for H-2 production. The metal center is changed from Ac to Pu. Electron-spin density calculations reveal a two-electron oxidative process (involving high-valent intermediates) for complexes [AnL] (An = P-Pu) along the catalytic pathway. The electrons are provided by both the actinide metal and the arene ring of ligand. This is comparable to the previously reported uranium catalyst ((ArO)-Ar-Ad,Me)(3)mesU (Ad = adamantine and mes = mesitylene). From the thermodynamic and kinetic perspectives, [PaL] offers appreciably lower reaction energies for the overall catalytic cycle than other actinide complexes. Thus, the protactinium complex tends to be the most reactive for H2O reduction to produce H2 and has the advantage of its experimental accessibility.

Automated summary

Actinide complexes capable of electrocatalytic H2O reduction were investigated in this study, with protactinium complex showing the lowest reaction energies and highest reactivity for producing H2. This complex offers the advantage of experimental accessibility and efficient conversion of H2O to H2.