Catalysis and reaction kinetics

[ Process control and online analysis - 1/2 ] Since they first appeared at the end of the 19th century, plastic materials have gradually become an integral part of our daily lives. While the benefits of these materials are undeniable, there is increasing concern about what happens to them at the end of their life. Therefore, in addition to reducing them at their source, the recycling of these polymer materials is now a major environmental priority.

The life cycle of hydrotreatment catalysts: from active phase genesis to catalyst recycling Catalysts are essential products for numerous industrial processes, including the hydrotreatment of oil feeds or bio-based feeds. Their properties stem from the active metal materials they contain, the value and criticality of which justify efforts to recover them from waste products. Accordingly, as a major producer of catalysts, one of IFPEN group’s key priorities is to apply the principles of the circular economy to them.

Understanding the chemical properties of the supports (alumina-gamma in particular) and active phases of heterogeneous catalysts is a challenge that requires a detailed atomic scale description of systems and the quantification of events that are rare on this scale: chemical reactions. Quantum simulation appears to be a suitable tool for trying to overcome this challenge. However, continuous improvement of numerical methodologies and atomistic models is required to determine the complex structure of active sites, on the one hand, and their reactivity (rate constant), on the other. By covering all these aspects, this PhD research has provided answers to this dual challenge, while exploring the contributions of machine learning (ML) to the understanding of the active sites...

Biomass conversion into chemical products and intermediates is increasingly being adopted to reduce the carbon footprint of the industry concerned. Among biomass-based resources, sugars are extremely attractive since they contain a lot of functional groups enabling their conversion to products of interest (alcohols, acids, etc.). For example, through fructose dehydration, it is possible to obtain 5-hydroxymethylfurfural (5-HMF), a molecule that can be used to produce polymers. Since the conversion of fructose to 5-HMF is catalyzed by Brønsted acids1, liquid acid catalysts in solution are currently used, but without the possibility of recycling this catalyst. The development of a solid acid catalyst is thus crucially important...

The dehydration of bio-based alcohols to form alkenes is a key reaction to obtain major chemical intermediates from biomass. It is efficiently catalyzed by zeolites presenting Brønsted acid sites and a crucial challenge is the control of its selectivity...