2026-10-13T01:26:56Z https://www.scidb.cn/oai

10.57760/sciencedb.011fy 2026-09-04T16:41:41Z

2026-09-04 DFT Study on the Selective Adsorption Mechanism of NOx and VOCs on Oxygen-Vacancy-Modified Anatase TiO2 (001) Surface doi:10.57760/sciencedb.011fy en Anatase titanium dioxide (TiO2) and its derivatives are considered as potential bifunctional catalytic materials for the simultaneous control of volatile organic compounds (VOCs) and nitrogen oxides (NOx) emissions. In this study, density functional theory (DFT) calculations were systematically performed to investigate the adsorption mechanisms of single molecules involved in the selective catalytic reduction of NH3 (NH3-SCR), namely NH3, O2, NO and NO2, as well as typical VOCs molecules (CH3Cl, C6H5Cl and C6H6O), on the oxygen-vacancy-containing anatase TiO2 (001) surface (Ovac-TiO2 (001)). Through analyses of adsorption energy, Bader charge, charge density difference and projected density of states, it is found that all SCR-related molecules exhibit strong chemisorption on the Ovac-TiO2 (001) surface, forming stable chemical bonds with surface Ti sites and undergoing pronounced orbital hybridization, with adsorption stability significantly higher than that of the selected VOCs molecules. In contrast, VOCs molecules are mainly weakly physisorbed, showing relatively weak interactions yet still capable of being activated by the surface. The introduction of oxygen vacancies significantly enhances the electron density and bonding capacity of surface active sites, leading to stronger adsorption and more pronounced bond activation for SCR molecules. This study reveals, at the molecular level, the selective adsorption and activation behavior of Ovac-TiO2 (001) toward VOCs and NOx, and clarifies that the oxygen-vacancy-induced orbital coupling and charge transfer constitute the essential electronic mechanism underlying the selective adsorption. This intrinsic mechanistic rule is independent of temperature conditions, thereby providing a theoretical basis for the design of efficient bifunctional catalysts for simultaneous removal of multiple pollutants. TiO2; oxygen vacancy; DFT; gaseous pollutants; adsorption characteristics Jiang Ruqing Yu Fengbo Peng Honggen Li Guobo EMBARGO https://creativecommons.org/licenses/by-nc-nd/4.0/ dataset Science Data Bank