Remaining coverage in associative desorption process

OCTAVIO JAVIER FURLONG; SERGIO JAVIER MANZI; VICTOR DANIEL PEREYRA

Chicago

Congreso; ACS 35th Great Lakes Regional Meeting; 2003

American Chemical Society

In this paper we have studied the kinetic of the dissociative adsorption of dimmers following by associative desorption. By means of the so called local evolution rules, we have obtained the system of coupled differential equations which describe the kinetics of the process. After truncate the hierarchy of equations the equilibrium solutions are obtained in exact form for the coverage and the nearestneighbor correlation functions, where the effects of the lateral interactions are discussed. The nonequilibrium kinetics is also analyzed, particularly the irreversible desorption. Since the desorption proceed from the reacting nearest neighbor monomers, a remaining coverage results from those isolated monomers when de mobility is neglected. The exact solution for 1D is eported. The thermal desorption spectra is also obtained from the kinetic equations. By using MC simulation we extend the study to the two dimensional case. The effect of the lateral interactions is also studied. The most interesting case appears for repulsive lateral interactions in the 2D case, where the curves are strongly dependent on the initial temperature and coverage.