Low-Temperature Benzene Abatement over Active Manganese Oxides with Abundant Catalytic Sites

Benzene is a typical volatile organic pollutant, and catalytic oxidation is promising for its abatement at low temperatures. Here, we prepared tunnel-structured hollandite-type manganese oxide (HMO) nanoparticles with abundant catalytically active sites (CASs). The HMO nanoparticles are more active than a traditional noble-metal catalyst, namely, Pt/Al2O3. The former catalyst can achieve 100% benzene conversion at 200 °C at a very high space velocity of 120 000 mL gcat–1 h–1. The results from relevant physicochemical characterizations and reaction kinetics studies demonstrate that the CASs are located at the tunnel openings of the HMO{001} surfaces. These CASs not only provide surface-active lattice oxygen species for benzene oxidation, but also efficiently activate O2 during the catalytic process. Moreover, HMO nanoparticles also have more CASs than HMO nanorods, thus leading to higher activity in benzene oxidation. This work may assist in the rational design of active transition-metal oxide catalysts fo...