Abstract

The century of complexity has come. Stephen Hawking’s statement “I think the next century will be the century of complexity” (‘millennium’ interview, January, 2000) became a widely cited prophecy. In this lecture, three approaches to grasping complexity of chemical reactions are presented:

1. thermodynamically consistent ‘gray-box’ approach;
2. chemical calculus (non-steady-state kinetic screening);
3. analysis of kinetic fingerprints

Within the ‘gray-box’ approach, a general structural form of the steady-state rate equation of the complex reaction is presented for linear reaction mechanism and for nonlinear reaction mechanisms, the so-called “kinetic polynomial”¹

Chemical calculus (non—steady-state kinetic screening) is driven by the technique of Temporal Analysis of Products (TAP), invented at Monsanto by John Gleaves in 1988. A rigorous theoretical development of this approach was presented later [2]. The main TAP -novelty was the controlled treatment of chemical system, in particular catalytic system, by a series of pulses of very small intensity. A sequence of infinitesimal steps produces a finite change of the system activity, hence the term ‘chemical calculus’ .

The goal of the analysis of kinetic fingerprints [3] is to find features and characteristics of observed kinetic behavior, based on which it is possible to resolve the detailed mechanism, its class or its family, and to determine its characteristics. A concept of complexity is supplemented by the concept of ‘simplexity’ to reflect the rich diversity of patterns which can be produced even by very simple systems. All approaches (see in detail [1]) are illustrated by examples taken from heterogeneous catalysis, i.e. complete and selective oxidation reactions

REFERENCES

1. G. B. Marin, G. Yablonsky “Kinetics of Chemical Reactions. Decoding Complexity”, J.Wiley-VCH (2011) 428p.
2. J.T. Gleaves, G.S. Yablonskii, P. Phanawadee and Y. Schuurman, “TAP-2. Interrogative Kinetics Approach”, Applied Catalysis A: General, 160, 55-88 (1997)
3. G. S. Yablonsky, D. Constales, G. Marin, “Coincidences in Chemical Kinetics: Surprising News about Simple Reactions”, Chem. Eng. Sci. 65(2010)2325-2332
4. ”Grasping Complexity”, Computers and Mathematics with Applications, special issue, editors G. Yablonsky and A. Gorban, Vol. 65, 13 ( 2013)