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 MnO x nanoparticles with adequately exposed defects. They exhibited an outstanding catalytic performance with a T 90 of 167 °C for acetone oxidation, which is 73 °C lower than that of bulk MnO x (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 MnO x exhibited impressive stability in long-term, cycling and water-resistance tests. Moreover, the possible mechanism for acetone oxidation over MnO x -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.

A novel CeO2/Co3O4 catalyst with a high catalytic activity has been designed and prepared by pyrolysis of metal–organic frameworks, and its catalytic performance was evaluated by the acetone catalytic oxidation reaction. The Co3O4–M catalyst with T 90 at 194 °C was prepared by pyrolysis of the MOF-71 precursor, which was 56 °C lower than that of commercial Co3O4 (250 °C). By the addition of cerium to the MOF-71 precursor, an enhanced CeO2/Co3O4 catalyst with T 90 at 180 °C was prepared. Importantly, the CeO2/Co3O4 catalyst exhibited superior stability for acetone oxidation. After 10 cycle tests, the conversion could also be maintained at 97% for at least 100 h with slight activity loss. Characterization studies were used to investigate the influence of cerium doping on the property of the catalyst. The results showed that addition of cerium could facilitate the expansion of the surface area and enhance the porous structure and reducibility at low temperature. Furthermore, the surface ratio of Co3+/Co2+ and mobile oxygen obviously improved with the addition of cerium. Therefore, the metal oxides prepared by this method have potential for the elimination of acetone.

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With the rapid development of industry, VOCs emissions harmful to the human body and the environment have also increased rapidly. At present, catalytic oxidation technology is regarded as one of...