Catalytic oxidation of volatile organic compounds over manganese-based catalysts: Recent trends and challenges

With the acceleration of industrialization and urbanization, the emission of volatile organic compounds (VOCs) has become a serious problem, so it is urgent to develop efficient methods to eliminate. Due to the high catalytic activity, strong stability and low cost, manganese-based catalysts as a kind of non-noble catalysts have been widely used in VOCs treatment, especially in abatement of VOCs by catalytic oxidation. The manganese-based catalysts with excellent properties have been widely used in VOCs removal, and a series of measures have been adopted to improve the oxidation activity of manganese-based catalysts. In this review, the effect of structure and composition of manganese-based catalysts (such as simple MnOx, mixed manganese-based metal oxides and supported manganese-based oxide catalysts) on catalytic oxidation of VOCs and the corresponding catalytic oxidation mechanism over different manganese-based catalysts are analyzed. The specific surface area (SSA), oxygen vacancies (OVs), reactive oxygen species, the valence of Mn and acid sites of manganese-based catalysts play an important role in VOCs oxidation. Finally, some challenges and suggestions are summarized and put forward for future research. This critical review is of great significance for systematic understanding and analysis of the VOCs oxidation over manganese-based catalysts, offering guidance to the preparation of highly efficient and cost-effective manganese-based catalysts for VOCs oxidation.