Acidic and basic groups introducing on the surface of activated carbon during the plasma-surface modification for changing of COS catalytic hydrolysis activity

Abstract

The Fe-based microwave coconut shell activated carbon (Fe/MCSAC) catalyst was surface modified by O2- and NH3-plasma. The catalyst modified by O2-plasma showed a lower catalytic activity than the unmodified sample, but the catalyst modified by NH3-plasma was improved dramatically. Fourier Transform Infrared Spectroscopy (FTIR) results showed that -COOH and -NH2 groups can be generated after by O2- and NH3-plasma modification, respectively. The theoretical calculation results indicated that acidic -COOH group showed some inhibition to the hydrolysis of carbonyl sulfide (COS), but -NH2 could improve it by bonding with the H atoms of H2O.