title: Periodic DFT study of acidic trace atmospheric gas molecule adsorption on Ca- and Fe-doped MgO(001) surface basic sites.
abstract: The electronic properties of undoped and Ca- or Fe-doped MgO(001) surfaces, as well as their propensity toward atmospheric acidic gas (CO2, SO2, and NO2) uptake was investigated with an emphasis on gas adsorption on the basic MgO oxygen surface sites, O(surf), using periodic density functional theory (DFT) calculations. Adsorption energy calculations show that MgO doping will provide stronger interactions of the adsorbate with the O(surf) sites than the undoped MgO for a given adsorbate molecule. Charge transfer from the iron atom in Fe-doped MgO(001) to NO2 was shown to increase the binding interaction between adsorbate by an order of magnitude, when compared to that of undoped and Ca-doped MgO(001) surfaces. Secondary binding interactions of adsorbate oxygen atoms were observed with surface magnesium sites at distances close to those of the Mg-O bond within the crystal. These interactions may serve as a preliminary step for adsorption and facilitate further adsorbate transformations into other binding configurations. Impacts on global atmospheric chemistry are discussed as these adsorption phenomena can affect atmospheric gas budgets via altered partitioning and retention on mineral aerosol surfaces.
authors: Departments of Chemistry and Chemical and Biochemical Engineering, University of Iowa , Iowa City, Iowa 52242, United States.
authors: Jonas
authors: J
authors: Baltrusaitis
authors: Courtney
authors: C
authors: Hatch
authors: Roberto
authors: R
authors: Orlando
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry; D004583:Electrons; D007501:Iron / Q000737:chemistry*; D008277:Magnesium Oxide / Q000737:chemistry*; D009585:Nitrogen Dioxide / Q000737:chemistry; D011789:Quantum Theory; D013458:Sulfur Dioxide / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000393:Air Pollutants; D013458:Sulfur Dioxide; D002245:Carbon Dioxide; D008277:Magnesium Oxide; D007501:Iron; D009585:Nitrogen Dioxide; D002118:Calcium