MPI Colloquia Series: Prof. Gregory S. Yablonsky, Chemical Calculus: A New Paradigm of Chemical Kinetics

The Max Planck Institute Magdeburg invites you to its series of colloquia. Top-class scientists, invited by the Max Planck Institute Magdeburg, give a survey of their research work. Everybody who is interested, is invited to attend.

Abstract

A new paradigm for understanding the complexity of chemical reactions materials and a new approach to creating and understanding the complex solid active materials, catalysts, are proposed. It focuses on non-steady-state studies and challenges the traditional methods of design/studies of model systems or high-throughput screening of composition libraries under steady-state conditions. The approach is a further development of Temporal Analysis of Products (TAP) – method which experimental technique and methodology, and theory and different applications as well have been proposed by Gleaves (1988) and Gleaves and Yablonsky (1997). In the TAP-approach, systematic small stepwise changes in catalyst surface composition are combined with precise kinetic characterization after each change to elucidate the evolution of catalyst properties and provide information on the relationship between surface composition and kinetic properties. Three principles of the TAP-experiment are the following ones: (1) Insignificant change of catalyst composition during the single pulse; (2) Controlled change of catalyst composition during the series of pulses; (3) Uniformity of the active zone regarding its composition.

Based on the new theory (so called Y-procedure) and corresponding software, the Thin-Zone-TAP-reactor (TZTR)-experiments provide with unique data, i.e. the non-steady-state concentration, transformation rate and uptakes/releases in the active catalytic zone without any a priori assumption about the type of kinetic dependence. Then, the TAP-approach will be used for determining the number of active sites and kinetic parameters of active materials, and, finally, for revealing the detailed mechanism of complex catalytic reaction.

The presented approach will be illustrated by the examples related to reactions of complete and partial oxidation, and decomposition of ammonia.

Ideas of Chemical Calculus which theory and methodology recently were described in detail can be expanded into many different areas and systems, e.g. for design of sensors, semiconductors and drugs etc.