title: DFT study of coverage-depended adsorption of NH3 on TiO2-B (100) surface.
abstract: A previous study showed that TiO(2)-B (100) surface is very unique. It is characterised by high activity and a loose structure. In this study, we studied the adsorption of ammonia on TiO(2)-B (100) surface at coverages ranging from 1/6 ML to 1 ML using ab initio density functional calculations. We also investigated the adsorption of an isolated ammonia molecule on TiO(2)-B (001) surface to compare the different activities of TiO(2)-B (100) and (001) surfaces towards NH(3). The results showed that the TiO(2)-B (100) surface is more reactive towards NH(3) molecule than TiO(2)-B (001) surface, and the Lewis acid site on TiO(2)-B (100) surface is more acidic. The decrease rate of the average molecular adsorption energy of NH(3) with coverage on TiO(2)-B (100) surface is substantially lower than that on a rutile (011) surface above 1/2 ML coverage due to the open structure of TiO(2)-B (100) surface. The average molecular adsorption energy shows a linear dependence on the coverage of y = 111.0 - 36.3x on TiO(2)-B (100) surface. The possibility of NH(3) molecule onto the Ti(5c) site is nearly equal to forming a dimer with adsorbed NH(3) on TiO(2)-B (100) surface at 5/6 ML coverage.
authors.affiliation: State Key Lab of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Xinmofan Road, 5#, Nanjing, Jiangsu Province 210009, China.
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Guo
authors.forename: Weijia
authors.initials: W
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Fang
authors.forename: Lu
authors.initials: L
authors.lastname: Cai
authors.forename: Yudan
authors.initials: Y
authors.lastname: Zhu
authors.forename: Linghong
authors.initials: L
authors.lastname: Lu
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Lu