A statistical rate theory description of CO diffusion on a stepped Pt(111) surface

Abstract

The statistical rate theory approach is used to describe far-from-equilibrium diffusion of carbon monoxide on a stepped Pt͑111͒ surface at low total coverages. Under nonequilibrium conditions, migration of adsorbates from terraces to steps, where adsorbates are more strongly bound, can occur. An expression for the molecular transport rate between terraces and steps is derived in terms of an equilibrium exchange rate, and the instantaneous chemical potentials of the molecules adsorbed on the terraces and along the steps. The theory contains no free parameters. Both the equilibrium exchange rate and the chemical potentials are obtained in the framework of a lattice gas model. The time evolution of the populations of steps and terraces is calculated and used to fit the available experimental data in order to evaluate the activation barrier of diffusion on terraces and the associated prefactor.

Adsorbate aggregation and relaxation of low-frequency vibrations

“…This geometry is important since steps are always present at surfaces and they generally attract adsorbates to their edges. 11 While the macroscopic coverage is low for this case, the local coverage is high.…”

Adsorption–desorption kinetics and chemical potential of adsorbed and gas-phase particles

“…5͒ and Ward's formalism. 17 From our comments, it is clear that employing the latter formalism for analysis of surface diffusion does not make sense.…”

Step‐Mediated Anisotropic Adsorption and Condensation of tert‐Butylamine on Cu(111)

“…[9] Because of the Smoluchowski effect, [10] the redistribution of electrons at step sites creates a local electric dipole, which has been characterized by STM and electrostatic force microscope. [11] The asymmetric electronic structure at the step edges could affect the adsorption and desorption, [12][13][14][15][16][17][18][19] diffusion, [20][21][22][23] and chemical reactivity of molecules. [5,24,25] For example, nucleophilic molecules such as benzene prefer to bind to the electron-poor region at the upper step edges.…”