Density functional theory adsorption

Hammer B, Hansen L B and Norskov J K 1999 Improved adsorption energetics within density functional theory using revised Perdew-Burke-Enerhof functionals Phys. Rev. B 59 7413-21... 

Figure 6.35. Potential energy diagrams for adsorption and dissociation of N2on a Ru(0001) surface and on the same surface with a monoatomic step, as calculated with a density functional theory procedure. [Adapted from S. Dahl, A. Logadottir, R. Egberg, J. Larsen, I. Chorkendorff,...

Figure 6.36. Calculated variation in the heats of adsorption of molecular CO and NO compared with the heats of adsorption of the dissociation products. Open symbols follow from the Newns— Anderson model, closed symbols from density functional theory. [Adapted from B. Hammer and J.K. N0rskov, Adv. Catal. 45 (2000) 71.]...

Ge, Q., Song, C. and Wang, L. (2006) A density functional theory study of CO adsorption on Pt—Au nanopartides. Computational Material Science, 35, 247-253. 

Schwerdtfeger, P., Lein, M., Krawczyk, R.P. and Jacob, Ch. (2008) The adsorption of CO on charged and neutral Au and Au2. A comparison between wave-frmction based and density functional theory. Journal of Chemical Physics, 128, 124302-1-124302-10. 

Forda, M.J., Hoft, R.C. and Gale, J.D. (2006) Adsorption and dimerisation of thiol molecules on Au(lll) using a Z-matrix approach in density functional theory. Molecular Simulation, 32, 1219-1225. 

Density Functional Theory (DFT) has shown that low-coordinated sites on the gold nanoparticles can adsorb small inorganic molecules such as O2 and CO, and the presence of these sites is the key factor for the catal5dic properties of supported gold nanoclusters. Other contributions, induced by the presence of the support, can provide parallel channels for the reaction and modulate the final efficiency of Au-based catalysts. Also these calculations extended for the adsorption of O and CO on flat and... 

While in previous ab initio smdies the reconstructed surface was mostly simulated as Au(lll), Feng et al. [2005] have recently performed periodic density functional theory (DFT) calculations on a realistic system in which they used a (5 x 1) unit cell and added an additional atom to the first surface layer. In their calculations, the electrode potential was included by charging the slab and placing a reference electrode (with the counter charge) in the middle of the vacuum region. From the surface free energy curves, which were evaluated on the basis of experimentally measured capacities, they concluded that there is no necessity for specific ion adsorption [Bohnen and Kolb, 1998] and that the positive surface charge alone would be sufficient to lift the reconstmction. 

Watson GW, Wells RPK, Willock DJ, Hutchings GJ. 2001. A comparison of the adsorption and diffusion of hydrogen on the 111 surfaces of Ni, Pd, and Pt from density functional theory calculations. J Phys Chem B 105 4889-4894. 

The GvdW Theory A Density Functional Theory of Adsorption, Surface Tension, and Screening... 

Conventional bulk measurements of adsorption are performed by determining the amount of gas adsorbed at equilibrium as a function of pressure, at a constant temperature [23-25], These bulk adsorption isotherms are commonly analyzed using a kinetic theory for multilayer adsorption developed in 1938 by Brunauer, Emmett and Teller (the BET Theory) [23]. BET adsorption isotherms are a common material science technique for surface area analysis of porous solids, and also permit calculation of adsorption energy and fractional surface coverage. While more advanced analysis methods, such as Density Functional Theory, have been developed in recent years, BET remains a mainstay of material science, and is the recommended method for the experimental measurement of pore surface area. This is largely due to the clear physical meaning of its principal assumptions, and its ability to handle the primary effects of adsorbate-adsorbate and adsorbate-substrate interactions. 

Numerous quantum mechanic calculations have been carried out to better understand the bonding of nitrogen oxide on transition metal surfaces. For instance, the group of Sautet et al have reported a comparative density-functional theory (DFT) study of the chemisorption and dissociation of NO molecules on the close-packed (111), the more open (100), and the stepped (511) surfaces of palladium and rhodium to estimate both energetics and kinetics of the reaction pathways [75], The structure sensitivity of the adsorption was found to correlate well with catalytic activity, as estimated from the calculated dissociation rate constants at 300 K. The latter were found to agree with numerous experimental observations, with (111) facets rather inactive towards NO dissociation and stepped surfaces far more active, and to follow the sequence Rh(100) > terraces in Rh(511) > steps in Rh(511) > steps in Pd(511) > Rh(lll) > Pd(100) > terraces in Pd (511) > Pd (111). The effect of the steps on activity was found to be clearly favorable on the Pd(511) surface but unfavorable on the Rh(511) surface, perhaps explaining the difference in activity between the two metals. The influence of... 

Nitrogen adsorption isotherms were measured with a sorbtometer Micromeretics Asap 2010 after water desorption at 130°C. The distribution of pore radius was obtained from the adsorption isotherms by the density functional theory. Electron microscopy study was carried out with a scanning electron microscope (SEM) HitachiS800, to image the texture of the fibers and with a transmission electron microscope (TEM) JEOL 2010 to detect and measure metal particle size. The distribution of particles inside the carbon fibers was determined from TEM views taken through ultramicrotome sections across the carbon fiber. 

Physical properties of calcined catalysts were investigated by N2 adsorption at 77 K with an AUTOSORB-l-C analyzer (Quantachrome Instruments). Before the measurements, the samples were degassed at 523 K for 5 h. Specific surface areas (,S BEX) of the samples were calculated by multiplot BET method. Total pore volume (Vtot) was calculated by the Barrett-Joyner-Halenda (BJH) method from the desorption isotherm. The average pore diameter (Dave) was then calculated by assuming cylindrical pore structure. Nonlocal density functional theory (NL-DFT) analysis was also carried out to evaluate the distribution of micro- and mesopores. 

Galea NM, Kadantsev ES, and Ziegler T. Studying reduction in solid oxide fuel cell activity with density functional theory-effects of hydrogen sulfide adsorption on nickel anode surface. JPhys Chem C 2007 111 14457-14468. 

Using perturbation theory. Hammer and Nprskov developed a model for predicting molecular adsorption trends on the surfaces of transition metals (HN model). They used density functional theory (DFT) to show that molecular chemisorption energies could be predicted solely by considering interactions of a molecule s HOMO and LUMO with the center of the total d-band density of states (DOS) of the metal.In particular. 

Density Functional Theory Research on Oxygen Adsorption on Pyrite (100) Surface... 

---