The adsorption behaviors of CO and H-2 on FeO surface: A density functional theory study

摘要

Density functional theory (DFT) calculations have been employed to investigate the adsorption behaviors of CO and H-2 on various feO surfaces in order to explore the mechanism process in the conversion of feO to Fe and predict the main growth orientation of metallic iron precipitated on feO surfaces. For adsorption of CO onto the feO(100) and feO(110) surfaces, the CO tends to adsorb to the Fe sites through the C-Fe bonds formed on both surfaces. For adsorption of CO onto the feO(111) surface, both Fe and O sites are active enough for the chemisorptions of CO. Moreover, the CO2 species is generated on the surface when CO adsorbs to the O top site. For adsorption of H-2 onto three FeO surfaces, the least and most stable configurations are the adsorptions of H-2 onto the FeO(100) and feO(111) surfaces, respectively. Especially, the H-2 molecule dissociates heterolytically and forms one O-H bond and one Fe-H bond when H-2 adsorbs to the feO(110) surface. In addition, the H2O species is generated on the surface when H-2 adsorbs to the O top site on feO(111) surface. (C) 2016 Elsevier B.V. All rights reserved.