@article {132,
	title = {Electronic Properties and Reactivity of Simulated Fe3+ and Cr3+ Substituted α-Al2O3 (0001) Surface.},
	journal = {Journal of Physical Chemistry C},
	volume = {116},
	year = {2012},
	note = {CAPLUS AN 2012:1152034(Journal; Online Computer File)},
	month = {2012///},
	pages = {18847 - 18856},
	publisher = {American Chemical Society},
	abstract = {Metal oxide-based minerals naturally contain transition metal impurities isomorphically substituted into the structure that can alter the structural and electronic properties as well as the reactivity of these metal oxides.  Natural α-Al2O3 (corundum) can contain up to 9.17\% (wt./wt.) Fe2O3 and 1.81\% (wt./wt.) of Cr2O3.  Here the authors report on changes in the structural and electronic properties of undoped and doped α-Al2O3 (0001) surfaces using periodic d. functional theory (DFT) methods with spin unrestricted B3LYP functional and a local at. basis set.  Both structural and electronic properties are altered upon doping.  Implications for doping effects on photochem. processes are discussed.  As metal oxides are major components of the environment, including atm. mineral aerosol, DFT was also used to study the effect of transition metal impurities on gas/surface interactions of a model acidic atm. gas mol., CO.  The theor. results indicated that the presence of Fe3+ and Cr3+ impurities substituted on the outer layer of natural corundum surfaces reduces the propensity toward CO adsorption relative to the undoped surface.  However, CO-surface interactions resemble that of bulk α-Al2O3 when the impurity is substituted below the 1st surface layer.  The presence and location of the mineral dopant significantly altered the structural and electronic properties and gas/surface interactions studied here. [on SciFinder(R)]},
	keywords = {carbon monoxide adsorption iron chromium substituted alumina surface, electronic property reactivity iron chromium substituted alumina surface},
	isbn = {1932-7447},
	author = {Baltrusaitis, Jonas and Hatch, Courtney and Orlando, Roberto.}
}
@article {140,
	title = {Periodic DFT Study of Acidic Trace Atmospheric Gas Molecule Adsorption on Ca- and Fe-Doped MgO(001) Surface Basic Sites.},
	journal = {Journal of Physical Chemistry A},
	volume = {116},
	year = {2012},
	note = {CAPLUS AN 2012:993259(Journal; Online Computer File)},
	month = {2012///},
	pages = {7950 - 7958},
	publisher = {American Chemical Society},
	abstract = {The electronic properties of undoped and Ca- or Fe-doped MgO(001) surfaces, as well as their propensity toward atm. acidic gas (CO2, SO2, and NO2) uptake was investigated with an emphasis on gas adsorption on the basic MgO oxygen surface sites, Osurf, using periodic d. functional theory (DFT) calcns.  Adsorption energy calcns. show that MgO doping will provide stronger interactions of the adsorbate with the Osurf sites than the undoped MgO for a given adsorbate mol.  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 obsd. 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 atm. chem. are discussed as these adsorption phenomena can affect atm. gas budgets via altered partitioning and retention on mineral aerosol surfaces. [on SciFinder(R)]},
	keywords = {iron calcium doped magnesia atm gas adsorption DFT},
	isbn = {1089-5639},
	author = {Baltrusaitis, Jonas and Hatch, Courtney and Orlando, Roberto.}
}
