Description du sujet de thèse

With the exhausting of the finite fossil resources, the chemical industry has to shift towards renewable raw materials where the use of renewable biomass appears to be of great interest. Numerous factors encourage transition from oil to biomass, including climate changes as well as global and national energy security. Due to significant difference in composition and properties of fossil and renewable resources, a complete re-design of the value chains upon the shift from naphtha to biomass feedstocks was proposed. This approach combines, after separation from lignin, a depolymerization of the complex biomass-derived polymers, such as cellulose and hemicelluloses, and a selective defunctionalization of the obtained monomers into novel platform chemicals. In this regard, 5-(hydroxymethyl)furfural (HMF) presents a very promising platform chemical as an intermediate for production of renewable polymers, fuel additives, as well as other commodities and fine chemicals.1-4 However, efficient production of HMF poses a major challenge owing to high reactivity of this compound and its tendency to resinification and formation of undesirable humins. Modest yields were reported for transformation of D-glucose into HMF, while higher performances were achieved for D-fructose into HMF production.
Catalytic activity of bases for the isomerization has been known since 19th century. Acids also exhibit catalytic activity for the isomerization.5 In particular, isolated atoms of Sn,5 Ti,6 or Hf7 embedded into a hydrophobic matrix hold promise as Lewis acid catalysts for isomerization. Nevertheless, bases are less expensive and can be synthesized in a simpler way compared to Lewis acid catalysts.
In this PhD offer, we aim to develop inorganic heterogeneous base catalysts belonging the phosphates family of compounds in order to achieve efficient isomerization of glucose. The challenge resides in obtaining pure compounds exhibiting high surface area, accessible catalytic sites and high chemical stability. These kinds of materials will be synthesized in aqueous media by a mere precipitation or by using the hydrothermal methods. The obtained compounds will be characterized by different techniques available at IRCELYON such as PXRD, SEM-TEM, BET, ICP-OES, FT-IR, Raman, calorimetry…
The synthesized materials will be tested under batch reactor conditions, according to the previously described procedure.8 During the screening, parameters, such as temperature, reaction time, and substrate concentration, will be systematically varied. In these tests, the first assessment of the catalytic activity of the prepared materials will be performed and the most promising catalysts in terms of activity and selectivity will be identified using the different analytical techniques available at IRCELYON such as HPLC-.
References
1. Delidovich, I.; Leonhard, K.; Palkovits, R., Cellulose and hemicellulose valorisation: an integrated challenge of catalysis and reaction engineering. Energy Environ. Sci. 2014, 7 (9), 2803-2830.
2. Delidovich, I.; Hausoul, P. J. C.; Deng, L.; Pfützenreuter, R.; Rose, M.; Palkovits, R., Alternative monomers based on lignocellulose and their use for polymer production. Chem. Rev. 2016, 116 (3), 1540-1599.
3. Davidson, M. G.; Elgie, S.; Parsons, S.; Young, T. J., Production of HMF, FDCA and their derived products: a review of life cycle assessment (LCA) and techno-economic analysis (TEA) studies. Green Chem. 2021, 23 (9), 3154-3171.
4. Slak, J.; Pomeroy, B.; Kostyniuk, A.; Grilc, M.; Likozar, B., A review of bio-refining process intensification in catalytic conversion reactions, separations and purifications of hydroxymethylfurfural (HMF) and furfural. Chem. Eng. J. 2022, 429, 132325.
5. Moliner, M.; Román-Leshkov, Y.; Davis, M. E., Tin-containing zeolites are highly active catalysts for the isomerization of glucose in water. Proc. Natl. Acad. Sci. U.S.A. 2010, 107, 6164-6168.
6. Gounder, R.; Davis, M. E., Titanium-Beta Zeolites Catalyze the Stereospecific Isomerization of D-Glucose to L-Sorbose via Intramolecular C5–C1 Hydride Shift. ACS Catal. 2013, 3 (7), 1469-1476.
7. Botti, L.; Kondrat, S. A.; Navar, R.; Padovan, D.; Martinez-Espin, J. S.; Meier, S.; Hammond, C., Solvent-Activated Hafnium-Containing Zeolites Enable Selective and Continuous Glucose–Fructose Isomerisation. Angew. Chem. Int. Ed. 2020, 59 (45), 20017-20023.
8. Souza, R. O. L.; Fabiano, D. P.; Feche, C.; Rataboul, F.; Cardoso, D.; Essayem, N., Glucose–fructose isomerisation promoted by basic hybrid catalysts. Catal. Today 2012, 195 (1), 114-119.

Contexte de travail

The PhD work will be conducted at IRCELYON, a laboratory dedicated to catalysis, mainly heterogeneous, which will also perform the tasks of catalysis and characterization of acid-base properties in the liquid phase.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

no identified risks

Informations complémentaires

Required Skills
The selected candidate has to show good marks during his/her M1&M2 also. He/Her has to show strong interests in materials science and heterogeneous catalysis fields. Good knowledge in X-ray diffraction techniques will be highly appreciated alongside the different analytical techniques such as HPLC and GC-MS. Good ability to work and communicate in English is strongly recommended since this project involve an Austrian partner.