Metal-organic frameworks for new technological and environmental applications
- Autores: Marta Mon Conejero
- Directores de la Tesis: Jesús Ferrando Soria (dir. tes.), Emilio Pardo (codir. tes.)
- Lectura: En la Universitat de València ( España ) en 2019
- Idioma: español
- Tribunal Calificador de la Tesis: Donatella Armentano (presid.), Samia Benmansour Souilamas (secret.), Antonio Leyva Pérez (voc.)
- Programa de doctorado: Programa de Doctorado en Química por la Universitat de València (Estudi General) y la Universitat Politècnica de València
- Materias:
- Enlaces
- Tesis en acceso abierto en: TESEO
- Resumen
The work described in this report is within the field of Materials Science and Coordination Chemistry, since it focuses on the rational design of new materials, specifically, porous coordination polymers (PCPs), also called metal-organic frameworks (MOFs), and its use in diverse applications of high technological and/or environmental interest.
The main objectives of this thesis are to obtain new porous coordination polymers, and the study of their properties for the capture or encapsulation of heavy metals (gold, mercury or rare earths) or organic species (different drugs or dyes), for gas sorption, as well as for the in-situ synthesis of sub-nanometric metal clusters (sMCs) of interest in catalysis. Thus, we have shown the importance of this type of materials in different technological areas.
The MOFs developed in this doctoral thesis have a two-fold relevance. On the one hand, they allow reducing the presence of pollutants in aquatic ecosystems, to limits that are permissible by the World Health Organization (WHO). On the other hand, they can be used as heterogeneous catalysts to carry out reactions in a more sustainable way.
In particular, the following points have been carried out: 1. Design and synthesis of new MOFs, with pores of different size, shape and functional groups, using for this purpose diverse oxamidate proligands derived from amino acids.
2. Post-synthetic modification of the obtained MOFs, as well as of others previously reported by members of the group, in order to improve or introduce new properties in them, or even to synthesize new species within their channels, such as sub-nanometric metal clusters.
3. Characterization of the materials using techniques such as: elemental analysis (EA), infrared spectroscopy (IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD) and N2 or CO2 adsorption.
4. Study of the properties and applications of the resulting materials. Some of them have been evaluated in collaboration with other research groups.
The present thesis has been structured in five sections, being the first introductory. Where, a brief historical review has been made from the coordination polymers to the MOFs, detailing how the contributions of some scientists in the field (Robson, Hoskins, Yaghi, Kitagawa, Férey, among others), as well as the advances in crystallography and the single-crystal X-ray diffraction technique contributed to the development and study of these materials. Then, the classification of the coordination compounds and the terminology used is shown. Next, the properties that MOFs can present are described, emphasizing their porosity, since it is the feature that has aroused the most interest. This is because its porous nature allows the diffusion of species in its pores, presenting a fascinating host-guest chemistry, which can be modulated by controlling the size, shape and reactivity of the pores. Furthermore, some of their applications are described, giving examples of representative MOFs that possess them, as well as showing, in each case, which are the determining factors that make them usable for such purposes. This section concludes justifying the choice of the synthetic strategy employed, so that the advantages of using oxamate and oxamidate ligands are shown, as well as the preparation of metalloligands to form 3D MOFs. In addition, a review is made of the compounds obtained by pioneering research groups working in this chemistry, among which it is our research group.
The second section includes the works (articles 1-7) on the synthesized MOFs that are capable of capturing organic or inorganic contaminants from water. It should be noted that this section contains two publications (articles 4 and 6) that do not directly concern the capture of pollutants in aqueous media, but rather the host-guest interactions that are established between a series of drugs and MOFs (article 4) and the discrimination of a mixture of lanthanides in non-aqueous media (article 6). These publications have been included in this section, since they allow elucidating the host-guest interactions responsible for the capture of pollutants. The third section includes publications (articles 8-9) in which post-synthetic methods (PSMs) have been used to provide materials with different properties, such as ferroelectric or gas sorption. In this way, it is shown how the use of this strategy allows designing materials for specific applications. The fourth section contains the publications (articles 10-12) in which post-synthetic modifications have been used, in particular, to obtain MOFs with catalytic application. Finally, in the fifth section the conclusions of this thesis are collected.
