Thermodynamics/Molecular modeling

Biomass conversion using chemical products and intermediates is increasingly being adopted to reduce the carbon footprint of this industry. Among biomass-based resources, sugars are extremely attractive since they contain a lot of functional groups enabling their conversion into products of interest (alcohols, acids, etc.). This conversion requires the use of catalysts, including heterogeneous catalysts based on zeolites with Lewis acidity , which have demonstrated strong potential, due to the presence of a tetravalent metal in the lattice position.

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...

The gradual loss of autonomy of lithium-ion batteries, used in our cell phones and electric vehicles, is notably linked to the formation of a layer known as a Solid Electrolyte Interphase (SEI), which builds up between one of the electrodes and the battery electrolyte. The formation of this SEI layer (Figure 1) was studied theoretically in this thesis using molecular modeling to improve the understanding of its thermodynamic and kinetic aspects. The PhD research initially focused on compiling a database of the principal degradation reactions involved by calculating the reaction and activation energies using DFT. The results used in KMC simulations then revealed that salts such as Li2CO3 and Li2O, derived from electrolyte degradation, play a crucial role. Simulations are also used to predict the loss of battery capacity as a function of the initial composition of the SEI layer (Figure 2) and hint the importance of considering other salts such as LiF resulting from degradation...

Reactive fluid transport simulation has multiple applications - flows in porous media, combustion, process engineering - and requires thermodynamic equilibrium calculations (also knows as “flash” calculations). However, these calculations can take a long time and, as they are involved in large numbers in the simulations carried out, in practice they limit the latter to systems containing few chemical species or to restricted time and space scales...

Everybody knows that lithium-ion batteries, used in cell phones, computers, etc., gradually lose capacity and eventually fail. This loss of capacity is primarily due to a layer known as the SEI, which forms between one of the battery’s electrodes and the electrolyte (see Figure). This layer already appears after the first battery charge/discharge cycle, and grows over time, consuming lithium ions. The process is irreversible and therefore detrimental to battery capacitye...

What chemical engineer has never dreamed of having access to a tool that can directly identify a fluid (pure substance or mixture) on the basis of characteristics necessary to a given application context? This Holy Grail could become a reality thanks to the field of Chemoinformatics and its methods...

The olefin oligomerization reaction provides access to a broad range of key compounds in the fuel, petrochemical and fine chemistry sectors...

The field of electrolyte thermodynamics is a strategic one for IFPEN since it contributes to a number of its existing technological innovations, as well as those currently being developed...

Supported by its recognized experience in the development of energy production solutions, IFPEN has acquired in-depth expertise in the field of materials for functional use. Today, this expertise is being harnessed to address the emerging challenges of the energy transition...

Ensuring compatibility between polymers and fluids is essential in numerous industrial sectors: in the automotive sector, for example, the resistance of materials used in the fuel supply system is a vital consideration.