Com. N-type active carbon was comminuted, demineralized (originally 18.38%), carbonized 3h1700 degrees C in N-2, and oxidized with (11.35:1.92:86.68 or 22.69:1.93:75.25 wt. %) mixture of O-2+H2O+(N-2 +Ar) in a fluidized bed reactor. Surface oxygen functionalities were examd. by H2O vapor adsorption, thermal decompn., and potentiometric titration. The acid-base nature was related to the O-2 concn. in the oxidant mixt. Tltration disclosed various surface groups ranging from 3 to 10 in pK(a). As a metal catalyst, the active carbon carrier thus obtained had a well-developed surface and texture with the C substance burnt to low degree only and was generally better to that oxidized with acids in the liq. phase.