Hi, do you know how to locate a reaction at the surface of a porous zone ? (I should perform surface reaction, which can be done only if I have "wall" boundary, but I should supply O2 from there and I use porous zone) Thank you in advance

It same my simulation too. You can set reaction in porous zone by, Define-Reaction > Restrict-Reaction

Yes Reaction active in porous media only

No Reaction active in non-porous media only But you have to use some reaction (not all-reaction) in porous zone or you have many porous zone. You must use User-Defined-Subroutines to solve it.

Thanks, I've recently found a way using "User Defined Functions", it's a very powerful tool