Ultraviolet photoelectron spectra for WnN2 2 (n51 – 8) clusters produced by addition of atomic and molecular nitrogen on W anion clusters are presented. Evidence is provided that molecular chemisorption of N2 is more stable than the dissociative one on tungsten anion clusters consisting of eight atoms or less, which is completely different from the results on tungsten bulk surfaces. A general t...

Molecular chemisorption at a metal surface is a key step for many processes, such as catalysis, electrochemistry, surface treatment, tribology and friction. Modeling with density functional theory is largely used on these systems. From a detailed comparison with accurate micro-calorimetric data on ten systems (involving ethylene, cyclohexene, benzene, naphthalene, CO, O2, H2, methane, ethane), ...

We consider an island growth mechanism wherein species adsorbed on top of two-dimensional islands diffuse to the edge and are then incorporated. A simple matrix formulation is developed for this random-walk problem which allows exact calculation of the growth probability distribution, neglecting island rearrangement. Furthermore, we also show how related trapping probabilities can be calculated...

The bond-energy bond-order (BEBO) model of chemisorption allows an estimate to be made of the interaction energy between a gaseous specie and a solid surface as a function of either bond length or bond order, i.e., the length or order of either the gas-surface bond being formed or the bond of the gaseous molecule being broken. The relationship between bond energy and either bond length or bond ...

Ethanol is the preferred solvent for the formation of self-assembled monolayers (SAMs) of thiolates on gold. By applying a thin film sensor system, we could demonstrate that even the best commercial qualities of ethanol contain surface-active contaminants, which can compete with the desired thiolates for surface sites. Here we present that gold nanoparticles deposited onto zeolite X can be used...

This project aims to develop new porous hydrogen storage materials which utilize molecular chemisorption of hydrogen rather than mere physisorption, and ultimately do this in low weight hybrid materials. Stronger binding of hydrogen should result in greater capacity and lower operating pressures at room temperature. These studies should lead to the design and synthesis of hydrogen storage mater...

adsorption of co molecule on the vanadium surface has been studied by using of the dft method with lanl2dz,6-31g* and 6-31g** basis sets by gga approximation of theory. using periodic first principles simulations we investigate the interaction of oxygen molecule with regular v (100) surface. the limitation of this approach is the use of thin metallic slabs with a limited range for their coverag...

The structural evolution of small copper clusters of up to 15 atoms and the dissociative chemisorption of H2 on the minimum energy clusters are studied systematically using density functional theory. The preferred copper sites for chemisorption are identified and the transition state structures and activation barriers for clusters four to nine atoms are determined and found to be inconsistent w...