[Ahsan Khan]

Hi,
I am simulating a problem in 2D in which hydrogen, nitrogen and oxygen enters from an inlet with certain specific mole fractions (known). then in the domain, there is a catalytic surface at which hydrogen and oxygen combine to form steam. the reaction in exothermic and the reaction follows Arrhenius equation. can someone please help me on how to do this surface reaction. I need to find out the mole fraction of hydrogen at the outlet and the temperature contour of the device. the picture of the problem is attached. kindly guide me.