Catalyzed Reaction
 

Hi, I have a big problem with a reaction modelling! I want to model a reaction between gaseous species. The reaction is catalyzed by a solid species distributed on cylindric pellets (the support). Using the option Wall Surface I limit the reaction on the surface but I'm not able to define the amount of surface that is actually active.What is the way in which I can define the percentage of surface that is active for the reaction?