A comparative study of modified cotton biochar and activated carbon based catalysts in low temperature SCR

A series of Mn-CeOx-based catalysts loaded on modified cotton biochars and commercial activated carbon were studied to investigate the selective catalytic reduction (SCR) of NO at low temperatures. The physicochemical properties of these catalysts were investigated by a variety of characterization methods. The results indicated that the co-activated cotton biochar may be a potential material for use as a low temperature SCR catalytic support instead of the commercial activated carbon (AC). Mn-CeOx/biochar by co-activation (COA) exhibited a higher specific surface area, surface acidity and Mn4+/Mn3+ ratio than the other catalysts. The XRD analysis indicated that Mn-CeOx was more dispersed on the surface of the cotton biochar (COA) than the other supports. In addition, there were more adsorbed oxygen species and oxygen functional groups on the surfaces of the Mn-CeOx/biochar (COA) catalysts. These properties of Mn-CeOx/biochar (COA) assisted the SCR reaction and the N-2 selectivity. Moreover, the rich adsorbed oxygen species and oxygen functional groups on the surfaces of the Mn-CeOx/biochar (COA) catalyst promoted the oxidation of NO to NO2, which resulted in high SCR activity. (C) 2015 Elsevier Ltd. All rights reserved.