The present PhD thesis explores the use of Metal-organic frameworks (MOFs)in heterogeneous catalysis. Particularly MOF-derived materials in CO2 valorization reactions.
In the Introduction, I describe history and fundamental elements of MOFs as well as possible applications of these materials in catalysis. I also outline the research done over MOF-mediated materials, including manufacture and applications.
Chapter 2. describes a new method to control phase composition of MOF derived solids via addition of water during pyrolysis, i.e. steam pyrolysis, using Basolite F300 and In@ZIF-67 as MOF precursors. The resulting solids were tested incarbon dioxide hydrogenation. We performed a detailed investigation and comparison between samples prepared with and without water addition. Ultimately, we demonstrated the difference in the catalytic performance between pyrolyzed and steam-pyrolyzed samples.
In Chapter 3. we examine MOF-74 as a platform to obtain a bimetallic Ni-Co catalyst for the dry reforming of methane (DRM). DRM involves the conversion of CO2 and CH4, the most important greenhouse gases, into syngas, a stoichiometric mixture of H2 and CO that can be further processed via Fischer–Tropsch chemistry into a wide variety of products. However, the devolvement of coke resistant catalysts, especially at high pressures, is still hampering commercial applications. This approach allows synthesizing bimetallic systems with high metal content uniformly distributed within a graphitic carbon shell. The bimetallic Ni-Co@CMOF 74 catalyst showed better catalytic results in comparison with monometallic materials. This is attributed to synergistic effects of Ni and Co that result in a much slower formation of coke.
Chapter 4. reports the use of MOF-derived Ni@CMOF-74 catalysts in thephotothermal conversion of CO2 to CH4. We investigate in detail the roots of the difference in catalytic performance caused by pyrolysis at different temperatures. Furthermore, we explore the recyclability of the catalyst in batch conditions and test our catalyst in the continuous flow reactor. Finally, as a proof of the concept we performed an outdoor experiment using the ambient solar irradiation as a main source of energy.
The final chapter of this thesis provides a comprehensive summary of the conducted research. It not only highlights the key findings and contributions made in this study but also addresses the challenges associated with MOF-mediated materials. Moreover, it offers a perspective on the potential avenues for further development in the field.
| Date of Award | May 28 2023 |
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| Original language | English (US) |
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| Awarding Institution | - Physical Sciences and Engineering
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| Supervisor | Jorge Gascon (Supervisor) |
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