Electrocatalytic Mechanisms in Manganese Oxide Systems

Electrocatalytic conversion of oxygen lies at the heart of sustainable energy technologies, including fuel cells, metal–air batteries and water‐splitting devices. Manganese oxide presents an abundant, low‐cost alternative to noble metals, offering a rich spectrum of valence states (Mn2+, Mn3+ and Mn4+), tunable defect chemistry and diverse crystal structures that together govern its catalytic performance. Key mechanistic insights reveal that oxygen vacancies modulate the adsorption energy of reactants, while mixed valence states facilitate charge transfer and enable bifunctional activity towards both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Structural engineering—through phase transformation, proton exchange or controlled annealing—can enhance electronic conductivity, stabilise surface oxygen species and optimise reaction pathways. Synergistic coupling with carbonaceous supports or secondary oxides further promotes active site dispersion and mitigates degradation under cycling conditions. Collectively, these advances outline a rational framework for the design of manganese–oxide electrocatalysts with high activity, durability and cost‐effectiveness for next-generation energy devices.

Research from Nature Portfolio

Recent studies have demonstrated that proton exchange on layered Li2MnO3 yields a protonated Li2-xHxMnO3-n phase with a contracted interlayer spacing and reduced unstable O 2p holes. This structural reconfiguration, coupled with an optimised Mn3.7+ valence state, enhances electronic transport and suppresses structural degradation, delivering superior ORR activity and long-term stability. The work employs theoretical calculations to link fewer O 2p holes to structural robustness, while the narrower interlayer distance fosters rapid charge transfer. This dual optimisation of charge state and lattice geometry provides a guiding principle for the rational design of layered alkali-containing metal oxides as robust electrocatalysts.

Electrocatalytic Mechanisms in Manganese Oxide Systems publication trend

The graph below shows the total number of articles in electrocatalytic mechanisms in manganese oxide systems across all publications each year (not limited to Nature Index journals).

Technical terms

Oxygen reduction reaction (ORR): Electrochemical conversion of O₂ to water or hydroxide ions, fundamental to fuel cells and metal–air batteries.

Oxygen evolution reaction (OER): Electrochemical oxidation of water to generate O₂, essential for electrolysers and rechargeable metal–air devices.

Oxygen vacancy: A lattice defect where an oxygen atom is missing, altering the local electronic environment and enhancing catalytic activity.

Valence state: The oxidation number of manganese ions (e.g., Mn2+, Mn3+, Mn4+), which influences charge transfer pathways and surface reactivity.

Half-wave potential: The electrode potential at which the current reaches half of its limiting value in voltammetry, used to gauge catalyst activity.

References

1. Progress in Development of Nanostructured Manganese Oxide as Catalyst for Oxygen Reduction and Evolution Reaction. Energies (2021).
2. Boosting oxygen reduction activity and enhancing stability through structural transformation of layered lithium manganese oxide. Nature Communications (2021).
3. In Situ Electrochemical Mn(III)/Mn(IV) Generation of Mn(II)O Electrocatalysts for High-Performance Oxygen Reduction. Nano-Micro Letters (2020).
4. Rich Surface Oxygen Vacancies of MnO2 for Enhancing Electrocatalytic Oxygen Reduction and Oxygen Evolution Reactions. Advanced Energy and Sustainability Research (2021).