Defective Ultrafine MnOx Nanoparticles Confined within a Carbon Matrix for Low-Temperature Oxidation of Volatile Organic Compounds.

The development of catalysts for volatile organic compound (VOC) treatment by catalytic oxidation is of great significance to improve the atmospheric environment. Size-effect and oxygen vacancy engineering are effective strategies for designing high-efficiency heterogeneous catalysts. Herein, we explored the in situ carbon-confinement-oxidation method to synthesize ultrafine MnOx nanoparticles with adequately exposed defects. They exhibited an outstanding catalytic performance with a T90 of 167 °C for acetone oxidation, which is 73 °C lower than that of bulk MnOx (240 °C). This excellent catalytic activity was primarily ascribed to their high surface area, rich oxygen vacancies, abundant active oxygen species, and good reducibility at low temperatures. Importantly, the synthesized ultrafine MnOx exhibited impressive stability in long-term, cycling and water-resistance tests. Moreover, the possible mechanism for acetone oxidation over MnOx-NA was revealed. In this work, we not only prepared a promising material for removing VOCs but also provided a new strategy for the rational design of ultrafine nanoparticles with abundant defects.