Surface coverage dynamics for reversible dissociative adsorption on finite linear lattices

Enrique Mercado; Hyun Tae Jung; Changho Kim; Alejandro L Garcia; Andy J Nonaka; John B Bell

doi:10.1063/5.0171207

Surface coverage dynamics for reversible dissociative adsorption on finite linear lattices

J Chem Phys. 2023 Oct 14;159(14):144107. doi: 10.1063/5.0171207.

Authors

Enrique Mercado¹, Hyun Tae Jung², Changho Kim¹, Alejandro L Garcia³, Andy J Nonaka⁴, John B Bell⁴

Affiliations

¹ Department of Applied Mathematics, University of California, Merced, California 95343, USA.
² Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea.
³ Department of Physics and Astronomy, San Jose State University, San Jose, California 95192, USA.
⁴ Center for Computational Sciences and Engineering, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.

PMID: 37823463
DOI: 10.1063/5.0171207

Abstract

Dissociative adsorption onto a surface introduces dynamic correlations between neighboring sites not found in non-dissociative absorption. We study surface coverage dynamics where reversible dissociative adsorption of dimers occurs on a finite linear lattice. We derive analytic expressions for the equilibrium surface coverage as a function of the number of reactive sites, N, and the ratio of the adsorption and desorption rates. Using these results, we characterize the finite size effect on the equilibrium surface coverage. For comparable N's, the finite size effect is significantly larger when N is even than when N is odd. Moreover, as N increases, the size effect decays more slowly in the even case than in the odd case. The finite-size effect becomes significant when adsorption and desorption rates are considerably different. These finite-size effects are related to the number of accessible configurations in a finite system where the odd-even dependence arises from the limited number of accessible configurations in the even case. We confirm our analytical results with kinetic Monte Carlo simulations. We also analyze the surface-diffusion case where adsorbed atoms can hop into neighboring sites. As expected, the odd-even dependence disappears because more configurations are accessible in the even case due to surface diffusion.