Dissociative adsorption surface corrugation

Darling G R and Holloway S 1994 The role of parallel momentum in the dissociative adsorption of H2 at highly corrugated surfaces Surf. Sc/. 304 L461... 

Low activation energy values are indicative of corrugated surfaces. From the difference in the found energy barriers, it is also concluded that CO adsorption is the rate-determining step for CO dissociative adsorption, followed by the dissociation step. These findings suggest a precursor-mediated mechanism for CO dissociative adsorption. 

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... 

Ultimately, the exact dynamics study for dissociative adsorption of a diatomic molecule on a corrugated, static surface should include the lateral motion of the center of mass of the diatom, i.e., include six degrees of freedom. The 6D Hamiltonian could be written in terms of the gas-phase Jacobi coordinates (molecular coordinates) as... 

Direct route. Neurock and coworkers studied the adsorption and direct activation of CO over flat Co(OOOl), corrugated Co(ll — 20), and stepped Co(10 - 12) and Co(ll — 24) surfaces computationally. The barriers on flat and corrugated surfaces are all larger than 1.97 eV independent of CO coverages, whereas the stepped surfaces are much more active. Direct CO activation shows a strong dependence on the surface structure. The step sites, which contain the so called B5 sites, may act as the reaction center for the direct channel. Hu and coworkers found that the step sites were more favored in activating the direct CO dissociation compared to flat sites. 

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