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Title |
“Porphyrin and aluminum porphyrin-based porous polymer networks for carbon dioxide capture and conversion’’ |
Author
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Γαϊτάνου Δήμητρα
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Thesis advisor
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Βαμβακάκη, Μαρία
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Abstract |
During the past decades, environmental issues have attracted a lot of research and technological interest due to the climate changes, global warming and limitations of the energy resources. The rising levels of CO2 emissions which cause global warming, demand the development of novel processes based on advanced materials for CO2 capture and conversion. Porous organic polymers with appropriate properties, including large surface areas, narrow pore size distribution, high chemical and thermal stability and functional groups are excellent candidates for potential applications in CO2 capture and conversion. In this work, we present the synthesis of porous polymer networks based on porphyrin (Po) and aluminum porphyrin (Al-Po) moieties. The development of the porous polymeric materials is based on the synthesis of a tetra-methacrylate porphyrin cross-linker. The porous porphyrin network (Po-net) was synthesized by free-radical polymerization of the tetra-methacrylate porphyrin derivative using azobisisobutyronitrile (AIBN) as the initiator. Next, the aluminum porphyrin-based network (Al-Po-net) was synthesized by the metalation of the Po-net using dimethylaluminum chloride. After drying the networks under supercritical CO2 conditions, the morphology of the Po and Al-Po-net was characterized by scanning electron microscopy (SEM), while the successful network metalation was verified by Attenuated Total Reflection Fourier-transform infrared (ATR-FTIR) spectroscopy and by Energy-dispersive X-ray spectroscopy (EDS). The porous Po-net showed a high BET surface area of 622 m2g-1, while that of the Al-Po-net was lower at 167 m2g-1. Furthermore, the porous Po-net showed higher CO2 absorption in comparison with the Al-Po-net, 1.54 mmol/g and 0.64 mmol/g, respectively at 273 K. The catalytic performance of both polymeric networks, Po and Al-Po, was investigated for the cycloaddition of CO2 in epichlorohydrin using tetrabutylammonium bromide as a co-catalyst. The conversion of epichlorohydrin to the carbonate derivative was determined by proton nuclear magnetic resonance (1H -NMR) spectroscopy. The experimental results showed a high catalytic activity of Al-Po-net with a 93% conversion at 100oC, 1 atm and 24 h reaction time, while the Po-net exhibited a similar good performance with 88% conversion under the same reaction conditions. The catalytic conversion of epichlorohydrin to the cyclic carbonate was found to increase with the reaction temperature.
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Language |
Greek |
Issue date |
2020-03-11 |
Collection
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School/Department--School of Sciences and Engineering--Department of Materials Science and Technology--Graduate theses
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Type of Work--Graduate theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/b/c/3/metadata-dlib-user1649832036-29847.tkl
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Views |
137 |