Enhancement of the denitrification efficiency over low‐rank activated coke by doping with transition metal oxides

Abstract Low‐rank activated coke (AC) is widely used for industrial flue gas purification due to its multipollutant cooperative removal capability. To enhance the denitrification capacity of AC for the selective catalytic reduction (SCR) of NO with NH 3 , several transition metal (Fe, Mn, Ce, V) oxides were uniformly loaded into AC by solvent impregnation. Compared to untreated AC, modified AC showed excellent denitrification efficiency above 90%. N 2 adsorption‐desorption and Raman spectroscopy techniques were used to characterize the pore size distribution and crystal structure of AC samples. The introduction of transition metal oxides had little effect on the pore structure of AC but increased the nitrogen‐containing functional groups, which facilitated NO removal. Moreover, x‐ray photoelectron spectroscopy (XPS) was used to analyze the valence changes of metal elements before and after denitrification. After the reaction, the content increase of the low‐valence metal oxides indicated that the transition metal oxides were involved in the reaction of NO with NH 3 . High‐valence metal oxides oxidized NO to NO 2 , which reacts more easily with NH 3 , thereby increasing the denitrification efficiency. Importantly, in the presence of SO 2 , modified AC still presented high denitrification performance. This transition metal oxides doping method can effectively improve the ability of low‐rank AC to remove NO in multi‐contaminant flue gas.