Transfer in Heterogeneous Catalysis

Purely physical phenomena, namely the diffusion of reactants to the catalyst surface (in the majority of cases, to the inner surface of pores), the diffusion of products from this surface, and the transfer of heat evolved or absorbed in the course of the reaction are indispensable components of the heterogeneous catalystic process. To find the kinetics of a reaction, it is 

The effect of diffusion on the rate of a heterogeneous catalytic reaction is characterized by the efficiency factor of a catalyst, tj, defined as the ratio of the actual reaction rate to the rate that would be in the kinetic region under the same conditions. 

Let a single-route steady-state reaction occur in the spherical porous catalyst grain. It is convenient to transpose all terms of (1) to the right side, i.e., to represent the reaction equation in the following form  

Then if Bf is a reactant, the corresponding stoichiometric coefficient, bit will be negative if Bf is a product, bt will be positive. Reaction rate calculated per unit of the grain volume (not the volume of the bed of grains) will be denoted as co. Thus, 

Effective diffusion coefficient of substance Bt in the grain will be denoted as D, for the simplicity we assume , to be constant. 

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N. Satterfield, Mass Transfer in Heterogeneous Catalysis, M.I.T. Press, 1970. 

Satterfield, C.N., 1970, Mass Transfer in Heterogeneous Catalysis , MIT Press, Cambridge. Semenov, N.N., 1928, Z. Phys. Chem. 48, 571. 

Reprinted from Mass Transfer in Heterogeneous Catalysis by C. N. Satterfield with permission of The MIT Press, Cambridge, Mass. Copyright 1970 by the Massachusetts Institute of Technology. 

For gas-phase diffusion in small pores at low pressure, the molecular mean free path may be larger than the pore diameter, giving rise to Knudsen diffusion. Satterfield (Mass Transfer in Heterogeneous Catalysis, MIT, Cambridge, MA, 1970, p. 43) gives the following expression for the pore difTusivity ... 

Satterfield, C.N. "Mass Transfer in Heterogeneous Catalysis MIT Press Cambridge, MA, 1970 Chap. 1. 

Satterfield, C. N. Mass transfer in Heterogeneous Catalysis (MIT Press, Boston, 1970). 

Physico-chemical aspects of mass and heat transfer in heterogeneous catalysis. 

Sato, M., Takayama, N., Kurita, S., and Kwan, T., Nippon Kagaku Zasshi 92, 834 (1971). Satterfield, C. N., Mass Transfer in Heterogeneous Catalysis. MIT Press, Cambridge, Massachusetts, 1970. 

Satterfield, C. N. "Mass Transfer In Heterogeneous Catalysis" M.I.T. Press Cambridge, Mass., 1970 p. 16. Reprinted 1981, Krleger Publishing Company. 

Satterfield, Ch.N "Mass Transfer in heterogenous catalysis", MIT Press, Mass. (1970). 

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