The diffusion and desorption processes

Now we have to introduce the process of diffusion and desorption of the A particles. It is a straightforward procedure ab is changed by the diffusion 

These terms represent jumps of an A particle into the central empty site forming one or more AB pairs. Using equation (9.1.60) we obtain 

The A-desorption affects the A-density. We must only add simple terms like —k CA in the equation for the temporal evolution of the A-density. Here kA is a desorption constant, equation (9.1.42). 

The temporal evolution equations for FA (r), Xp AB, which are not shown in this Section are the same as in Section 9.1.1. 

We discuss the model described above firstly neglecting both diffusion and desorption [22], which makes it analogous to the original ZGB-model. We obtain for the critical points y = 0.395 0.005 and = 0.565 0.005, 

---