RésuméToday, the development of sustainable processes is in the spotlight due to the climate emergencies. Green Chemistry with its twelve principles developed by Paul Anastas, focuses on the development of alternative and more environmentally friendly processes. This branch of chemistry shows how concepts such as waste prevention, the use of renewable raw materials and catalysis are of great importance in making a process more sustainable. In this context, carbon dioxide (CO2) represents one of the most abundant, non-toxic and renewable carbon feedstocks. The possibility of reusing CO2 and transforming this molecule into value-added products such as cyclic carbonates, via addition into epoxides, makes this molecule interesting from a research point of view. Despite these interesting characteristics, the transformation of CO2 has a very high energy thermodynamic requirement. To overcome this problem, a suitable catalyst is essential to decrease the activation energy of the process and make it work in milder condition. In this context this Ph.D. dissertation finds its outlines. Among all the possible catalysts proposed in literature, one class of catalysts that has been little explored is that of bifunctional materials. The excellent catalytic performance shown by these heterogeneous catalysts seems to narrow the gap in terms of catalytic activity between heterogeneous and homogeneous catalysis in relation to this reaction.
The first Chapter of the dissertation introduces the reader into the field of heterogeneous catalysis and in catalysis applied for the conversion of carbon dioxide in cyclic carbonates. After this introductory chapter, the dissertation is splitted into two main sections.
A first part concerning the Chapter III is related to the study of the stability during catalysis of different materials based on carbon nanoforms (CNFs). On the other hand, Chapters IV and V are related to the second part of the thesis that put its attention in the design of different bifunctional materials based on polyhedral oligomeric silsesquioxanes and their application as a catalyst for the conversion of carbon dioxide with epoxides.
|la date de réponse||2023|
|Sponsors||Université de Namur & Università di Palermo|
|Superviseur||Carmela Aprile (Promoteur), Michelangelo Gruttadauria (Copromoteur), Guillaume Berionni (Président), Luca Fusaro (Jury), Francesco Giacalone (Jury) & Eric M. Gaigneaux (Jury)|