[kjwx109]

With Langmuir-Hinshelwood kinetics, the rate of a bimolecular reaction on a surface is proportional to [Cat]^2, where Cat is in mol/m2.  How can the expression be modified so the catalyst terms relates to the amount of catalyst charged (in g/L solution), rather than the concentration of sites on its surface?

More specifically, I understand that the order of say a hydrogenation, where LHHW kinetics apply, is first order with respect to a weight-based catalyst charge.  I am trying to reconcile this with the depiction of kinetics in terms of the surface concentration of catalytic sites.