Comparative study on the physicochemical properties and de-NOx performance of waste bamboo-derived low-temperature NH3-SCR catalysts

Waste bamboo-derived activated carbon (BAC), biomass char (BBC), and nitric acid-modified BACN and BBCN supports as well as commercial activated carbon (AC) and corresponding ACN were prepared for comparative study. Their denitrification performance in 100–250 °C decreased as BACN > ACN > BBCN > BAC > AC > BBC. BACN and ACN were separately loaded with different MOx (M = Mn, Ce, Fe, Cu, V) by wet impregnation. M/BACN showed slightly higher NO conversion than corresponding M/ACN. Mn/BACN exhibited the best denitrification performance with NO conversion of 92% at 200 °C. The physicochemical properties of supports and catalysts were characterized by BET, SEM-EDS, FTIR, XRD, and XPS. The results suggested that BAC was most sensitive to HNO3 modification, thereby BACN possessed much more surface functional groups. This was the main reason for BACN exhibiting the best denitrification performance among the supports. Loading metal oxides introduced more strong active sites sharply increasing the catalytic activity, even though decreased the surface area and decomposed a few surface functional groups. Mn/BACN mainly followed the L–H mechanism at low temperature. Rich surface functional groups on BACN could promote the adsorption and activation of NH3 and NO accelerating the reaction in L–H mechanism.