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

• MnCeOx/biochar by co-activation (COA) exhibited a higher specific surface area.
• MnCeOx/biochar (COA) exhibited a higher surface acidity.
• The Mn4+/Mn3+ ratio was higher in MnCeOx/biochar (COA).
• More adsorbed oxygen is present in MnCeOx/biochar (COA).
• MnCeOx/biochar (COA) demonstrated a higher selective catalytic reduction activity.

A series of MnCeOx-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). MnCeOx/biochar by co-activation (COA) exhibited a higher specific surface area, surface acidity and a Mn4+/Mn3+ ratio than the other catalysts. The XRD analysis indicated that MnCeOx 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 MnCeOx/biochar (COA) catalysts. These properties of MnCeOx/biochar (COA) assisted the SCR reaction and the N2 selectivity. Moreover, the rich adsorbed oxygen species and oxygen functional groups on the surfaces of the MnCeOx/biochar (COA) catalyst promoted the oxidation of NO to NO2, which resulted in high SCR activity.

Figure optionsDownload as PowerPoint slide