Oxygen binding energy

The potential of relevance for competitive adsorption of water may shift upon alloying Pt. The calculated ratio of water to oxygen binding energies at the UHV... 

Greeley J, Nprskov JK. 2005. A general scheme for the estimation of oxygen binding energies on binary transition metal surface alloys. Surf Sci 592 104-111. 

Trends in calculated oxygen reduction activity plotted as a function of the oxygen binding energy. (Reprinted with permission from ]oumal of Physical Chemistry B, 108, 17886 (2004). Copyright 2004 American Chemical Society.)... 

The d band model, including Pauli repulsion, can therefore be used to understand variations in oxygen binding energies in the periodic table. It turns out that a similar description can be used for a number of other adsorbates [4,18]. 

Figure 4.14 illustrates the interpolation principle [54,55]. It shows DFT calculations of the oxygen binding energy for a large number of alloys. The DFT values are compared to two different levels of model. Both models use the interpolation principle in one case the bonding to a site with two kinds of neighbors, A and B, on the same substrate is calculated as... 

Figure 6.18. Trends in oxygen reduction activity plotted as function of the oxygen binding energy (adapted from Ref. [117]). Solid line associative mechanism arrows rate determining processes dashed line associative mechanism.

Kuchynka et al. [125] studied the electrochemical oxidative dimerization of methane to C2 hydrocarbon species using perovskite anode electrocatalysts. Three designs of solid oxide fuel cells were used, including tubular and flat plate solid electrolytes. The maximum current density for the dimerization reaction at these electrocatalysts was related to the oxygen binding energies on the catalyst surface. The anodic reaction was ... 

A relatively low metal-oxygen binding energy, allowing anions to disengage and diffuse through the lattice. 

The possible contribution of alkoxy radicals to the formation of reaction products is already mentioned above. In this section we should emphasize that the relative probability of reactions (13) and (14) depends on the properties of the catalyst (oxygen binding energy E o ) and on the reaction temperature the higher the temperature and the lower the E o, the more probable is the reaction (13). In this case one may expect an increase of selectivity of partial oxidation to oxygenates. 

The main factors determining the efficiency of different oxides as catalysts for lower alkanes oxidation are the H-atom affinity of strong oxidizing surface sites and the oxygen binding energy. These thermochemical factors cause the rates and directions of free-radical reactions and, as a result, the catalytic activity and selectivity to certain products. 

These facts are indicative of a complex mechanism of the dehydroxylation process, which is not surprising if we keep in mind a high oxygen binding energy for this catalyst (see Table II). Also, they are suggestive of the possibility of reoxidation without intermediate formation of oxygen vacancies. 

Molecular Oxygen Binding Energies, BE, and Optimized Pt—O and O—O Distances (Rr o and / 0 0), and Perpendicular Distance from the O Atom Closer to the Plane of the Platinum Cluster (D) for Different [Pt(111)]1802 and [Pt(100)]1802 Configurations at Equilibrium Potential... 

In order to evaluate the effect of the B-site element similar studies were performed on LaBC>3 (B - Co, Mn, Fe, Cr) by Voorhoeve et al. (1976). The activity for CO oxidation rose as the tolerance factor increased, while it decreased with increasing radius of B ions. The lower B-oxygen binding energy was more favorable for the oxidation of CO, suggesting that the active site involved in the CO oxidation consists of B-O-B clusters. This might imply the participation of surface oxygen in this reaction. 

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