III International Conference

THE HETEROGENEOUS CATALYSIS LAWPP-I-63Kharlamov V.F.Orel State Technical University, Orel, RussiaE-mail: Kharl@ostu.ruThere is defined a relation having a universal character and imposing a restriction uponkinetics of a catalytic reaction. A quantitative criterion for a definition of catalytic reactionmechanism is determined.Gas molecule chemisorption on the surface of solids is carried out through a precursorstate – an intermediate state conditioned on that that gas molecules captured with the surfacelost energy of forward and rotary movements not immediately, but during a period of ~ 10 -11 s.Being in a precursor state molecules react with adsorbed molecules of other nature. In thecase of catalytic reaction passing on the boundary of a solid and a gas mixture119( Σ M i )imolecules M i caught by a surface in a precursor state and pass in one of three possiblecompetitive states according to a condition:q = q +(1)1+ q2q3where q , q1 , q2,q3- flows of M i passed accordingly: q – from atmosphere into a precursorstate; q 1 – from a precursor state into atmosphere; q 2 – in a state of chemisorption; q 3 – in astate of a constituent of product molecule (or a particle of transient formation) of reaction.Equality (1) is carried out at an arbitrary point of time because of that that the life span ofmolecules in a precursor state is lesser of a typical period of relaxation on an adsorption layerfor many of orders. Therefore condition (1) imposes a restriction upon kinetics ofheterogeneous process just as conservation laws of impose restrictions upon possible nuclearreactions. Equality (1) is universal inasmuch as it is correct at the interaction of arbitraryatmospheres with the surface of arbitrary solids (including, when q = 30 ). Condition (1) canbe considered as a decree of nature as applied to heterogeneous processes.The energy of activation for chemical transformations with the participation of moleculesin a precursor state is considerably less than a potential barrier for competitive processes ofproduct molecule formation in the layer of chemisorbed particles. If the phase of aheterogeneous chemical reaction being described with condition (1) limits formation ofproduct or a product molecule are formed directly in this stage then for the reaction rate weobtain expression J = q3 = q − q1− q2. As an example we present results obtained at the