Ultra-Low-Temperature Ozone Abatement on α‑MnO<sub>2</sub>(001) Facets with Down-Shifted Lowest Unoccupied Orbitals ChenYaxin QuWeiye LiChao ChenJunxiao MaZhen TangXingfu 2018 Extraordinary catalytic performance at ultralow temperatures is energetically desirable for ozone converters equipped on commercial passenger aircrafts, but it remains a great challenge to achieve it. Here we synthesized sheet-shaped α-MnO<sub>2</sub> exposing a large percentage of reactive (001) facets, on which low-valence surface manganese ions and abundant surface oxygen vacancies act as catalytic sites. Compared with α-MnO<sub>2</sub> rods, α-MnO<sub>2</sub> sheets exhibited exceptional catalytic activity in ozone decomposition even at −55 °C due to the abundant catalytic sites. By using Mn L<sub>3</sub>-edge absorption spectroscopy and the frontier orbital theory, we found that α-MnO<sub>2</sub> sheets have down-shifted lowest unoccupied Mn 3d orbitals with respect to β-MnO<sub>2</sub>, which enables electrons to transfer from peroxide intermediates to catalytic sites more easily, thus accelerating the reaction rate even at very low temperatures in the stratosphere.