화학공학소재연구정보센터
Langmuir, Vol.18, No.4, 1112-1118, 2002
Kinetics of heterogeneous adsorption: Mean-field theory and simulations
We investigate the adsorption kinetics of particles on a lattice with nearest neighbor interactions. The coverage-dependent desorption rate must satisfy a simple relation resulting from the symmetry between occupied/unoccupied adsorption sites. Kinetic mean-field theories satisfying this requirement are proposed for a homogeneous surface with constant adsorption energy as well as a heterogeneous surface where the adsorption energies are independently and normally distributed. The mean field theories predict an equilibrium phase transition in both the homogeneous and heterogeneous systems. While a transition is actually present in the former case, the distribution of adsorption energies suppresses the transition in the latter. Nevertheless, comparison of the predictions with numerical simulations of the model shows that the mean-field theories provide an accurate description of the adsorption kinetics as long as the interparticle interaction-to-temperature ratio is weaker than the mean-field critical value.