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

Abstract

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 (V_Mn)-based Lewis pairs (LPs) for catalytic ozone decomposition. The presence of V_Mn induces the electronic restructuring in MnO, leading to the formation of V_Mn-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.