Benzene abatement catalyzed by Ceria-Supported platinum nanoparticles and single atoms

Abstract

Heterogeneous catalysis is one promising technology to abate benzene at relatively low temperatures, but it remains challenging to develop efficient catalysts owing to the difficulties in activating inert benzene molecules and cleaving the strong double bonds of O2. We present the importance of frontier band orbitals in catalyst design for benzene oxidation by correlating electronic structures with catalytic activities over ceria-supported platinum nanoparticles (Ptn/CeO2) or single atoms (Pt1/CeO2). Catalytic tests demonstrate that Ptn/CeO2 shows much higher catalytic activity and lower activation energy than Pt1/CeO2 under identical conditions. By combining the experimental results and theoretical calculations, we reveal that the high activity of Ptn/CeO2 mainly originates from the energy level of the frontier band orbitals, where the lowest unoccupied and the highest occupied band orbitals are energetically favorable for activating benzene and O2, respectively, thus rendering the temperatures required for complete oxidation of benzene significantly lower. Similar trends in activity are found in high-temperature combustion of CH4 and low-temperature oxidation of CO, implicating the universal importance of the energy levels of frontier band orbitals in catalytic oxidation. This work provides a strategy to rationally design high-performance catalysts that can efficiently abate pollutants for environmental protection.