SUBJECT
A new class of porous materials has been recently developed. It consists of hybrid inorganic-organic solids called MOFs (Metal Organic Frameworks). MOFs are porous solids built up from inorganic subnetworks (clusters, chains, or layers) and organic complexing molecules (phosphonates, carboxylates, sulfonates). These subnetworks often contain divalent (Zn2+,Cu2+, …) or trivalent cations (Cr3+, Al3+, …) connected to each other via organic groups such as carboxylates. The structures possess tunnels or cavities with pore sizes between 3 and 35Å. Such compounds could be an alternative route to zeolites for some applications such as sorption of gases, separation, and catalysis.
Cations of metallic sub-units can generate Lewis acid sites (coordinatively unsaturated sites on metallic cations), Bronsted acids (hydroxyl linked to one or more cations) and reducible metal centers in the case of solids based on iron or vanadium. As for the organic part, the possibility of introducing nitrogen functions on the ligand (amine, imine) allows one to obtain well located basic sites.
These MOFS contain adsorption sites and their nature and their concentration is well defined a priori. As this is not the case for most of the solids used in heterogeneous catalysis (especially due to the presence of defects and to important phenomena of surface relaxation), the subject of this thesis is to exploit this unique property of MOFs to study the relationship between qualitative and quantitative adsorption properties of these sites and their catalytic properties. In particular, the approach will consist in the spectroscopic study of the species adsorbed on these solids in reaction conditions (operando studies) for model catalytic reactions, whose rate and / or selectivity are known as specific of the nature (acid, basic, acid-base or redox) and / or the number of sites involved (alcohol dehydration, polymerization of heterocycles, …). The results will allow an assessment of the reaction mechanisms, which could be eventually extrapolated to other classes of materials.
This study will be supported notably by the experimental approaches specific to our laboratory, such as in situ adsorption of adapted, selected probe molecules and operando monitoring of the behavior of solids during the modulation of the number and the nature of the sites (selective poisoning of sites during reactions, adsorption of water, creation of controlled defects, …).
CONTEXT AND RESEARCH ENVIRONMENT
This PhD will be carried out in the Laboratory of Catalysis and Spectrochemistry (University of Caen, Normandy, FRANCE) within the research group “Surfaces and Environment”. The spectroscopic study of hybrid materials like MOFs has a preminent position in this team and can beneficiate of many national (including the Institut Lavoisier in Versailles for the synthesis of materials) and international (since 2007, two European projects, including one in progress) collaborations that give the opportunity to expand the doctoral training in other fields of science, developing and diversifying the academic and industrial contacts.
In addition, the regular publication of scientific results in the most prestigious international journals of chemistry (Angewandte Chemie, Chemical Society Reviews, Journal of the American Chemical Society, Chemistry of Materials, …), demonstrate that this topic and the related researches carried out at the LCS are recognized as at the top of the current research.
Candidate profile
The candidate should have the equivalent of a Master (obtained during the last two years) strongly oriented towards chemistry or physical chemistry, with a good knowledge in methods of material characterization and / or catalysis. Knowledge in vibrational spectroscopies and catalytic tests will be appreciated.
Contact:
Alexandre VIMONT Laboratoire Catalyse et Spectrochimie, ENSICAEN, Université de Caen, CNRS, 6 bd du Maréchal Juin, 14050 CAEN, France
e-mail : alexandre.vimont@ensicaen.fr
Web site of the laboratory : http://www-lcs.ensicaen.fr
Application:
Potential candidates should e-mail a cover letter, complete CV and contact information from two referees (recommendation letters are appreciated).
The position (3 years) will start in september, 2013. The Salary will be in line with the French regulations of PhD salaries, Approx. 1350 € net /month, including social benefits and health coverage.
Most relevant Published articles:
(1) Seo, Y. K.; Yoon, J. W.; Lee, J. S.; Hwang, Y. K.; Jun, C. H.; Chang, J. S.; Wuttke, S.; Bazin, P.; Vimont, A.; Daturi, M.; Bourrelly, S.; Llewellyn, P. L.; Horcajada, P.; Serre, C.; Ferey, G. Advanced Materials 2012, 24, 806.
(2) Guillerm, V.; Ragon, F.; Dan-Hardi, M.; Devic, T.; Vishnuvarthan, M.; Campo, B.; Vimont, A.; Clet, G.; Yang, Q.; Maurin, G.; Férey, G.; Vittadini, A.; Gross, S.; Serre, C. Angewandte Chemie International Edition 2012, 51, 9267.
(3) Vermoortele, F.; Ameloot, R.; Vimont, A.; Serre, C.; De Vos, D. Chemical Communications 2011, 47, 1521.
(4) Horcajada, P.; Salles, F.; Wuttke, S.; Devic, T.; Heurtaux, D.; Maurin, G.; Vimont, A.; Daturi, M.; David, O.; Magnier, E.; Stock, N.; Filinchuk, Y.; Popov, D.; Riekel, C.; Ferey, G.; Serre, C. Journal of the American Chemical Society 2011, 133, 17839.
(5) Ferey, G.; Serre, C.; Devic, T.; Maurin, G.; Jobic, H.; Llewellyn, P. L.; De Weireld, G.; Vimont, A.; Daturi, M.; Chang, J. S. Chemical Society Reviews 2011, 40, 550.
(6) Yoon, J. W.; Seo, Y. K.; Hwang, Y. K.; Chang, J. S.; Leclerc, H.; Wuttke, S.; Bazin, P.; Vimont, A.; Daturi, M.; Bloch, E.; Llewellyn, P. L.; Serre, C.; Horcajada, P.; Greneche, J. M.; Rodrigues, A. E.; Ferey, G. Angewandte Chemie-International Edition 2010, 49, 5949.
(7) Vimont, A.; Thibault-Starzyk, F.; Daturi, M. Chemical Society Reviews 2010, 39, 4928.
(8) Salles, F.; Maurin, G.; Serre, C.; Llewellyn, P. L.; KnoÌfel, C.; Choi, H. J.; Filinchuk, Y.; Oliviero, L.; Vimont, A.; Long, J. R.; Férey, G. Journal of the American Chemical Society 2010, 132, 13782.
(9) Devic, T.; Horcajada, P.; Serre, C.; Salles, F.; Maurin, G.; Moulin, B.; Heurtaux, D.; Clet, G.; Vimont, A.; Greneche, J. M.; Le Ouay, B.; Moreau, F.; Magnier, E.; Filinchuk, Y.; Marrot, J.; Lavalley, J. C.; Daturi, M.; Ferey, G. Journal of the American Chemical Society 2010, 132, 1127.
(10) Bourrelly, S.; Moulin, B. a.; Rivera, A.; Maurin, G.; Devautour-Vinot, S.; Serre, C.; Devic, T.; Horcajada, P.; Vimont, A.; Clet, G.; Daturi, M.; Lavalley, J.-C.; Loera-Serna, S.; Denoyel, R.; Llewellyn, P. L.; FeÌrey, G. r. Journal of the American Chemical Society 2010.
