Boreskov rule

This rule is based on a thermodynamic examination of catalytic systems and, as a natural consequence, an assumption on the relationship between the composition (and, as a result, the properties of the catalyst surface) and external conditions brought about by the reaction medium. The validity of the Boreskov rule for a large variety of catalytic systems indicates that the structural and chemical transformations of the catalyst surface induced by the reaction medium are indispensable indeed to heterogeneous catalysis. 

The consequence of the inevitable adaptation of a catalyst to the reac tion medium was formulated by G. Boreskov in 1947 as a particular rule In stationary conditions, the specific catalytic activity, SCA, of a heteroge neous catalyst (i.e., the rate of the catalytic reaction per unit of exposed surface of the catalyticaUy active phase) is approximately constant at a given temperature and the reaction medium composition, thus SCA being dependent only on the chemical composition of the active catalyst phase. At present, turnover frequency (TOF) of the active center is normally used instead of SCA to characterize the activity of the center, TOF being in direct proportion to SCA. The Boreskov rule is evidently valid for the TOF value, too. 

Changes in the catalytic activity of unit accessible surface or the specific catalytic activity (SCA) has attracted the attention of researchers. In the 1950s Boreskov formulated a rule for the approximate constancy of the SCA. According to this rule, the SCA for several metal and oxide catalysts remains approximately constant with significant variations of the surface and crystallite sizes under preparative conditions. Boreskov ascribed this con-... 

V.P. Zhdanov, Boreskov Horiuti Enomoto Rules for Reversible Heterogeneous Catalytic Reactions. Surf. Rev. Lett. 14 (3) (2007) 419 424. 

Georgii Boreskov, an eminent Soviet scientist in catalysis, devoted his research to the creation of an adequate physicochemical language for describing the phenomenon of heterogeneous catalysis, and he considered thermodynamics the fundamentals for the description. His analysis of the thermodynamic bases of catalytic processes produced the commonly accepted and experimentally proved Boreskov s rule on the approximate constancy of the specific catalytic activity ... 

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