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Dynamic diffusion and reaction in a porous solid catalyst layer

The overall reaction is A ⇀ B and is far from equilibrium under conditions here. Reactant A adsorbs reversibly over catalyst surface sites S: A + S ⇌ AS. Select Model 1 or 2, then click the Run button below. Click outside of input fields after changing values.

Select the "slow" rate determining step below: Model 1 (simple) or 2 (self-inhibiting).

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See space-time plot of rate, and average rate and conversion at bottom of page.

Slide to set inlet A conc:


Enter Kflow

Enter Kads

Enter Kdiff

Enter Thiele Modulus

Enter alpha

Enter B out scale factor

Enter cycling period

Enter square duty cycle % on



Gas profiles
catalyst layer

profiles in
catalyst layer

Average Rate (dimensionless turnover frequency) =



Average Conversion of A =

outer, gas-catalyst interface:

Space-Time plot of reaction rate

inner, sealed surface:

Click the Run button to start. Hit the enter key or click out of field after changing inputs.