Carbon based denitrification catalysts have attracted much attention in recent years due to their excellent thermal conductivity, well-developed pores, huge specific surface area and stable chemical properties, which provide better reaction conditions in SCR reactions, and have been used as carriers for denitrification catalysts by an increasing number of researchers. Carbon based carriers mainly include activated carbon (AC), carbon nanotubes (CNTs), activated carbon fibres (ACF), etc. Wu, Haimiao et al[32] loaded transition metal components such as Fe, Cr, Cu and Mn onto the activated carbon carrier by impregnation method, and the Mn(8%)/AC denitrification catalyst showed the highest denitrification efficiency (95%) at a temperature of 210°C. The Mn(8%)-Fe(8%)/AC denitrification catalyst had the most stable performance and the best catalytic denitrification efficiency. Yoshilawa et al[33] used The Mn2O3/ACF denitrification catalyst was prepared by Yoshilawa et al [33] using ACF as the carrier and Mn2O3 as the active component. The activity evaluation showed that the NO conversion rate could reach about 92% when the loading of Mn2O3 was 15% and the application temperature was 150°C.

MnOx/AC denitrification catalysts were prepared by impregnation method, and the experimental results showed that the NO conversion on the denitrification catalysts could reach more than 90% at below 200 °C. Moreover, the activity of the denitrification catalysts was significantly improved when Ce elements were doped in the MnOx/AC denitrification catalysts. Liu Qing et al [12] prepared MnOx-CeO2/PPSN denitrification catalysts by loading MnOx-CeO2 onto nitric acid-treated polyphenylene sulfide (PPSN) filter media using ultrasonic method; They also loaded Mn-Fe onto the active AFC [13] and achieved a NO conversion of 92% at a temperature of 200 °C. The MxOy/MWCNTs (M=Mn, Ce) series denitrification catalysts were prepared by isovolume impregnation using multi-walled carbon nanotubes (MWCNTs) pretreated with oxygen plasma as carriers. Tian et al [36] prepared different denitrification catalysts using nanotubes, nanorods and nanospheres as carriers and MnO2 as the active component, and investigated the effect of different carbon-based carriers on the catalytic activity of denitrification catalysts. Although the charcoal-based carriers have high catalytic activity, they are prone to spontaneous combustion when the flue gas temperature is high, which limits the use of charcoal-based denitrification catalysts.