Defect-based Lewis pairs on hydrophobic MnO mesocrystals for robust and efficient ozone decomposition

Catalytic ozone decomposition is a promising technique for eliminating ozone from the environment. However, developing redox-active catalysts that efficiently decompose ozone while maintaining robust performance under high humidity remains challenging. Herein, we develop a hydrophobic carbon-coated mesocrystalline MnO (Meso-MnO@C) featuring a high density of manganese vacancies (VMn)-based Lewis pairs (LPs) for catalytic ozone decomposition. The presence of VMn induces the electronic restructuring in MnO, leading to the formation of VMn-Mn acidic sites and adjacent lattice oxygen atoms as basic sites. These LPs act as electron donors and acceptors, facilitating rapid electron transfer and lowering the energy barrier for O3 conversion to O2. The hydrophobic carbon layer protects against water accumulation on Meso-MnO@C in humid conditions. As a result, the Meso-MnO@C achieves nearly 100% O3 decomposition at a high weight hourly space velocity of 1500 L⋅g−1 h−1, with rapid reaction kinetics and stable performance for 100 hours under 65% relative humidity. Designing catalysts that efficiently and sustainably break down O₃ in humid conditions remains a challenge. Here, the authors present a strategy for incorporating Lewis pairs into the catalyst as electron donor-acceptor sites to achieve robust O₃ decomposition in humid environments.