Plotting Surface Reaction Rate
 

I have set up a model of a CVD process similar to that in the CVD tutorial included with Fluent, but I can not get a value for the surface reaction rate. I have played with my activation energy of my reaction (lowered it substantially) to force the reaction well into the diffusion limited regime, but when I plot the surface reaction rates on my appropriate surfaces, I get zeros. The diffusion of my reagents in the fluid behaves as expected with the changes in activation energies, but I can not get any data related to the rate of reagent consumption. Any ideas? Thanks in advance.