Competitive adsorption of H2O/NH3 over graphite oxide surface Keith E. Gubbins, Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905 Density functional theory has been used to study reactive adsorption of NH3 on functionalized graphite oxide, with/without the presence of water. Functional groups studied includes carboxyl, hydroxyl and 1,2-ether groups. NH3+GO_COOH NH3+GO_1,2-ether In the absence of water, NH3 dissociates over carboxyl and 1,2-ether groups. The calculated reaction pathways show that the reaction is more favorable over carboxyl groups. H2O+GO_OH NH3+GO_OH When water is present it is preferentially adsorbed on the functional groups and prevents reaction of NH3. The results are consistent with recent experimental results, and suggest directions for designing improved materials for NH3 removal.