1554
Kinetic Resistance: Concept for Elecrochemical and Catalytic Kinetics

Wednesday, 8 October 2014: 16:40
Expo Center, 1st Floor, Universal 6 (Moon Palace Resort)
G. S. Yablonsky (Parks College of Engineering, Aviation and Technology, Saint Louis University, St. Louis, USA)
It is shown that the steady-state or pseudo-state of rate of complex chemical reaction with a single route can be presented in a form

Rate =    (Driving force)/ "Kinetic Resistance"                                               (1)

The driving force is related to the 'mass law expression' for the overall reaction.

The Kinetic Resistance (KR) has a Langmuirian form. It is linear regarding the concentration terms.  Coefficients of these terms are Arrhenius parameters or sums of the Arrhenius parameters.

Obviosly, this dependence is similar to the Ohms Law, i.e. rate, driving force and 'kinetic resistance', can be identified with current, voltage and resistance, respectively.

This equation is rigorously proven using graph theory for many classes of linear complex mechanisms which steps are linear regarding intermediates.

As for the non-linear mechanisms, it is rigorously proven for the single route mechanims under typical simplifying assumptions: (a)  presence of the rate-determining step;

(b) vicinity of the equlibrium.

In the general case, the rate of complex reaction can not be expressed explicitly as a function of concentration and temperature. It was proven that for the single-route complex reaction with the non-linear mechanism, the kinetic expression is a polynomial F( R, c, T), i.e. a Kinetic Polynomial (KP) , which is implicit regarding the reaction rate. However the thermodynamic branch of kinetic polynomial can be always presented in the form (1) using concepts of the 'driving force' and 'Kinetic resistance'. These resultants have been obtained using the algebraic theory of resultants (1) The concept of kinetic resistance was succefully applied for description of water-gas shift reaction over platinumcontaining catalyst (2)

1. Lazman, M.Z. and Yablonsky, G.S. (2008), in Mathematics in Chemical Engineering and Kinetics, Advances in Chemical Engineering, V.34, Elsevier, Amsterdam, pp.47-102

2. Marin, G, and Yablonsky, G.S., Kinetics of Chemical Reactiions: Decoding Complexity, Wiley-VCH, 2011, 428 pp.