Dissociation on metals

Luntz A C and Harris J 1991 CH dissociation on metals—a quantum dynamics model Surf. Sc/. 258 397... 

In this context, works [20, 21] should be mentioned, in which 0 2 ion-radicals were ESR detected in all samples of solution quickly frozen after initiation of H202 catalytic dissociation on metals and oxides (applied on A1203). The ion-radicals mentioned occur on the surface and desorb to the liquid phase, where, with high probability, they induce free radical processes. These results conform to the Weiss mechanism (6.3) of H202 dissociation on heterogeneous catalysts. 

Diatomic hydrogen gas can adsorb and dissociate on metal surfaces to produce atomic hydrogen [1,2]. The subsequent dissolution and diffusion of atomic hydrogen into metals can have two consequences for the performance of a... 

So far the 3D flat-surface model has been quite successful in providing qualitative and even some quantitative dynamics information for hydrogen dissociation on metals such as the role of hydrogen vibration and rotation in dissociative adsorption on Cu(lll) (104,114,117-119). However, the inherent limitation of the flat-surface model dictates that it cannot provide information on surface corrugation and its effect on molecular adsorption. One would like to investigate the effect of rotational orientation of diatomic molecules on chemisorption in the presence of surface corrugation. In order to obtain... 

The phenomenon that spiltover hydrogen hydrogenated the pyridine adsorbed on acidic sites of USY can be schematically expressed as a model shown in Rg. 3. The gas phase hydrogen is first dissociated on metal sites and then spillover to SiO support first, then cross the interface between Pt/Si02 and USY and finally move to acidic sites of USY zeolite through surface migration. Here, pyridine molecules bonded on USY acid sites acted as an acceptor for spiltover hydrogen. 

It is mentioned in Section 9.2 that the preparation of bimetallic nanoparticles by surface redox reactions occurs under a controlled atmosphere between a parent monometallic catalyst and the cation of the second metal dissolved in aqueous solution. However, the immersion of the parent catalyst in the solution may induce a modificahon of the metal particle size before the introduction of the ion of the second metal. In an aqueous medium, water molecules could penetrate between the metal-support interface and induce the migration of metal crystallites. Moreover, water and gas, for instance hydrogen, can adsorb and dissociate on metals, leading to a modification of their electronic properties. Consequently, it is important to study the stability of supported monometallic catalysts in an... 

Water can be partially or totally dissociated on metals to form hydroxyl and hydrogen or atomic oxygen and hydrogen. The driving force for dissociation is provided by the heat of formation of the dissociation fragments (OH, H, O) relative to the chemisorption bond of molecular water. 

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