Hierarchically Hollow MnO<sub>2</sub>@CeO<sub>2</sub> Heterostructures for NO Oxidation: Remarkably Promoted Activity and SO<sub>2</sub> Tolerance
Lei Chen, Chen Zhang, Yuxin Li, Chun-Ran Chang, Chi He, Qiang Lü, Yunsong Yu, Peigao Duan, Zaoxiao Zhang, Rafael Luque
Abstract
Thermochemical approaches of oxidizing NO to NO2 have been considered as the critical steps governing NOx purification technologies. However, developing efficient materials with boosted NO oxidation activity and strong SO2 resistance at low temperature still remains a significant challenge. This contribution discloses a versatile and scalable methodology for the design of hollow MnO2@CeO2 heterostructures for NO oxidation. Due to its hollow core–shell nanostructure with a high density of active oxygen vacancies and improved charge-transfer efficiency induced by the heterojunction interface, the resulting material exhibits remarkable low-temperature catalytic activity in NO oxidation (T50 at 196 °C and T92 at 275 °C), achieving over 69 °C of temperature reduction in comparison with the commercial Pt/Al2O3 catalyst (T50 at 275 °C). Remarkably, the SO2 tolerance of the hollow core–shell material is greatly enhanced due to the block accessibility of the mesoporous CeO2 shell (ECeO2,SO2 = −1.78 eV vs EMnO2,SO2 = −1.04 eV). This work exemplifies an alternative perspective in the design of high-performance hollow core–shell nanostructured catalysts for atmospheric pollutant purification and industrial thermal catalysis processes.