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Madkhali, Asma (2023) Synthesis of Porous Carbons and Their Applications in Gas Uptake. PhD thesis, University of Nottingham.

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Abstract

The need to mitigate the negative environmental impacts of fossil fuel usage and the growing scarcity of these fuels have motivated the exploration and implementation of alternative approaches for carbon dioxide reduction and energy storage. Porous materials have been identified as a viable solution among the various strategies available. Porous carbons have exhibited considerable potential for numerous applications in this domain. The present dissertation conducts an investigation into porous carbons, with a particular emphasis on different synthesis methods and material characterisation. Additionally, the study examines the potential of these materials in terms of energy storage and gas adsorption applications.

Using zeolites as templates for producing porous carbons is a hot topic as the resultant zeolite-templated carbons (ZTCs) have a high surface area along with a narrow pore size distribution compared to other porous carbons. However, the extensive use of acids to dissolve the template during the synthesis of ZTCs is a drawback. In this thesis, Chapter 3, a new approach was examined for dissolving the template (zeolite 13X). The results show a successful removal of the template without excessive use of acid. The methane storage using these carbons showed a superior capacity compared to some of the already existing benchmark materials.

Synthesising activated carbons from renewable, cheap biomass waste using two activating agents and different synthesis routes was examined in Chapter 4. In the approach, ginkgo leaves were converted into activated carbon for CO2 mitigation applications. The effects of the hydrothermal carbonisation temperature, direct K2C2O4-activation, and pre-washing of the char on the activated carbon porosities were examined. The high CO2 uptake at atmospheric pressure (up to 5 mmol/g) made the samples promising candidates for postcombustion CO2 capture applications.

The direct synthesis of heteroatom-doped activated carbons using a selfactivating organic salt (potassium hydrogen phthalate) was examined in Chapters 5 and 6. Urea and boric acid were added during the carbonisation of the self-activating salt and led to nitrogen doping. The addition of only the urea to the carbonisation mixture of the salt boosted the surface area and porosity of the produced carbons and thus their CO2 adsorption. On the other hand, the addition of boric acid to the salt-urea mixture had a negative effect on the porosity and the CO2 uptake capacity.

Item Type:	Thesis (University of Nottingham only) (PhD)
Supervisors:	Mokaya, Robert
Keywords:	zeolites, carbons, carbon dioxide reduction, biomass
Subjects:	Q Science > QD Chemistry > QD146 Inorganic chemistry T Technology > TJ Mechanical engineering and machinery > TJ807 Renewable energy sources
Faculties/Schools:	UK Campuses > Faculty of Science > School of Chemistry
Item ID:	73933
Depositing User:	Madkhali, Asma
Date Deposited:	26 Jul 2023 04:40
Last Modified:	26 Jul 2023 04:40
URI:	https://eprints.nottingham.ac.uk/id/eprint/73933

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