Kinetic Treatments for Catalyst Activation and Deactivation Processes based on Variable Time Normalization Analysis

Abstract

Progress reaction profiles are affected by both catalyst activation and deactivation processes occurring alongside the main reaction. These processes complicate the kinetic analysis of reactions, often directing researchers toward incorrect conclusions. We report the application of two kinetic treatments, based on variable time normalization analysis, to reactions involving catalyst activation and deactivation processes. The first kinetic treatment allows the removal of induction periods or the effect of rate perturbations associated with catalyst deactivation from kinetic profiles when the quantity of active catalyst can be measured. The second treatment allows the estimation of the activation or deactivation profile of the catalyst when the order of the reactants for the main reaction is known. Both treatments facilitate kinetic analysis of reactions suffering catalyst activation or deactivation processes.

Multi-nuclear, high-pressure, operando FlowNMR spectroscopic study of Rh/PPh3 – catalysed hydroformylation of 1-hexene

“…32 A recent report includes an example of an operando investigation of Rh/phosphite-catalysed hydroformylation using FlowNMR but with a limited amount of data and experimental details. 33 Landis recently reported a detailed kinetic study of Rh-catalysed hydroformylation using a static 10 mm reactor within a high-field magnet connected to liquid dosing and gas recirculation. 34 Here, we investigate the hydroformylation of 1-hexene in presence of [Rh(acac)(CO) 2 ] and PPh 3 by operando high-resolution FlowNMR spectroscopy from an actively mixed pressure autoclave using periodic cycles of interleaved 1 H NMR, 31 The first reaction was performed at 60 °C with 10 bar of H 2 /CO (1:1), where the autoclave was initially pressurised with H 2 for 1 h before adding CO to trigger the hydroformylation reaction.…”

Real Sociedad Española de Química Awards 2019

“…The Burés group gathers and exploits mechanistic understanding to improve catalytic organic reactions. In a Communication in Angewandte Chemie they used variable time normalization analysis for a kinetic treatment of catalyst activation and deactivation processes …”

Preise der Real Sociedad Española de Química 2019

“…Die Gruppe von Burés sammelt mechanistische Erkenntnisse und nutzt diese, um katalytische organische Reaktionen zu verbessern. In einer Zuschrift in der Angewandten Chemie verwendeten sie eine Zeitnormalisierungsanalyse für die kinetische Beschreibung von Prozessen bei der Aktivierung und Desaktivierung von Katalysatoren …”