In recent decades, researchers have developed a variety of low-temperature denitrification catalysts, including transition metal oxide denitrification catalysts, precious metal denitrification catalysts and ion-exchange molecular sieve denitrification catalysts. Among them, transition metal denitrification catalysts, such as those containing V, Mn, Fe, Co, Ni, Cr, Cu, W, Zr, La and other active components, have shown high catalytic activity for low-temperature SCR reactions. Due to the special valence electron configuration of Mn element (3d54s2), the valence state of Mn element is widely varied, including +2, +3, +4, +5 and some non-integer equivalents, which can achieve mutual conversion between different valence states of Mn to produce redox, which can promote the reduction of NO and thus the SCR reaction [5], and MnOx has a variety of surface active oxygen This leads to a large increase in the low-temperature catalytic activity of this denitrification catalyst [6-7]. For these reasons, MnOx-based denitrification catalysts have become a research hotspot for low-temperature SCR denitrification catalysts at home and abroad.

MnOx denitrification catalysts are mainly divided into two categories: non-carrier type and carrier type denitrification catalysts. This paper introduces the current research status of low-temperature MnOx-based SCR denitrification catalysts and provides an outlook on the next step of research.
Another effective way to improve the specific surface area and dispersion of denitrification catalysts and enhance their performance against H2O and SO2 is to load the active components onto a carrier with a large specific surface area. Since the catalytic activity and selectivity of loaded manganese denitrification catalysts are higher than those of non-negative manganese denitrification catalysts, the study of loaded manganese denitrification catalysts has become a hot topic of interest. At present, the main carriers used for the preparation of manganese denitrification catalysts are TiO2, Al2O3, carbon based materials, molecular sieves, ceramics, etc.

Low temperature SCR denitrification catalysts have many advantages such as low activity temperature and long service life, making them the main development direction for denitrification catalysts. At present, some progress has been made in the research of low temperature manganese based SCR denitrification catalysts, but there are many problems to be solved in the process of industrial application of these denitrification catalysts.