Abstract: Four kinds of active carbons(AC) were investigated,which were made of coconut shell(CS),hawthorn nut (HN), mountain peach nut(PN)and coal(C),respectively.Elementary analyses showed that HNACand PNACwere rich in oxygen-containing,however it was few in CSACand CAC.Oxygen-containing groups,especially carboxyl groups on active carbons were found to have a great influence on the reducibilities of active carbons.And yet,the carboxyl groups were abundant on HNAC and PNAC,but scarce on CSACand CACillustrated by Boehm's titration and NH₃-TPD,Meanwhile,HNAC and PNAC also exhibited much better performance on NOreduction than CSACand CAC.This revealed that oxygencontaining groups indeed acted as the reactive centers of NOreduction,especially —COO— was the most important.The reaction mechanism of NOreduction was thus proposed.

Key words: Active carbons, Adsorption, NO reduction