Tunable catalytic activity of cobalt-intercalated layered MnO2 for water oxidation through confinement and local ordering

• Published in: Journal of catalysis 2019-06, Vol.374 (C), p.143-149
• Main Authors: Ning, Jinliang, Furness, James W., Zhang, Yubo, Thenuwara, Akila C., Remsing, Richard C., Klein, Michael L., Strongin, Daniel R., Sun, Jianwei
• Format: Article
• Language: English
• Subjects: Atomic intercalation; catalysis (heterogeneous), electrocatalysis, solar (photovoltaic), mechanical behavior, superconductivity, magnetism and spin physics, water, materials and chemistry by design, synthesis (novel materials); Density functional theory; Layered materials; Oxygen evolution reaction
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2019.04.037

[Display omitted] •OER catalyzed by Co-intercalated layered MnO2 is studied theoretically.•Over-stabilization of intermediates on the surface results in a high overpotential.•Confinement of the interlayer destabilizes intermediates.•Co clustering at the interlayer space selectively stabilizes the *OOH intermediates.•The synergy of confinement and Co clustering improves the catalytic activity. The lowering of reaction overpotentials is a persistent and universal goal in the development of catalysts for (photo)electrochemistry, which can usually be facilitated by selectively stabilizing one reaction intermediate over another. In this mechanistic study of the oxygen evolution reaction (OER) catalyzed by cobalt-intercalated layered MnO2, we show that confinement effects and local cobalt atomic ordering in the interlayer space can be synergistically used to tune the adsorption energies of O, OH, and OOH reaction intermediates and the scaling relationship between them. In general, the interlayer confinement destabilizes the adsorption of intermediates for the OER, but clustering Co atoms can selectively stabilize the adsorption of OOH in particular. After considering both effects, our model predicts an overpotential of 0.30 V for the Co-intercalated MnO2 catalyzed OER, in excellent agreement with the experimental result of 0.36 V. These new insights explain the enhanced catalytic performance of MnO2 by intercalating atoms and illuminate a route for engineering non-toxic precious-metal-free catalysts through designed layered materials.