Proton Conduction and Lithium Extraction in Chromium (III) Phosphonate Metal-Organic Frameworks

dc.contributor.advisorShimizu, George Kisa Hayashi
dc.contributor.authorZhang, Jinfeng
dc.contributor.committeememberHeyne, Belinda Josiane M.
dc.contributor.committeememberThangadurai, Venkataraman
dc.contributor.committeememberLing, Chang-Chun
dc.contributor.committeememberDemadis, Konstantinos
dc.date2024-05
dc.date.accessioned2024-01-29T18:27:12Z
dc.date.available2024-01-29T18:27:12Z
dc.date.issued2024-01-24
dc.description.abstractPhosphonate metal-organic frameworks (MOFs) present potential candidates for functional materials due to their inherent structural stability and the capacity for synthetic manipulation. However, a trade-off often arises in the form of compromised crystallinity and structural predictability, which poses a significant hurdle in fabricating porous materials. This thesis focuses on an in-depth investigation into the synthetic approach and the performance of ordered chromium phosphonate MOFs concerning proton conduction and lithium extraction. An approach utilizing a hydrogen-bonded metal-organic framework (HMOF) intermediate was adopted to balance crystallinity and stability and evaluated thoroughly in Chapter 3. Salts made of hexaaquochromium(III) cations and phosphonate anions were dehydrated to form stable MOFs. Intriguingly, this method maintains partial structural crystallinity and engenders a varied pore size distribution during the thermal dehydration conversion step. This variability, in turn, affects the proton conductivity by providing different proton mobility efficiency, with as broad as two orders of magnitude in proton conduction among different MOFs. Chapter 4 explores the use of the HMOF to MOF strategy, focusing on the impact of reagent stoichiometry, ligand geometry, and binary solvent systems on proton conduction. It reveals that fine-tuning reactant stoichiometry is a viable method for enhancing proton mobility channels. The chapter also investigates how ligand geometry influences proton conductor performance, finding that more flexible structures maintain conductivity regardless of structural changes caused by water percolation. Additionally, it highlights the role of binary solvent systems in HMOF synthesis, noting that higher solvent content in HMOFs leads to lower crystallinity and reduced proton conduction after thermal dehydration, though the dehydration process itself minimally affects proton conductivity. Chapter 5 pivoted focus to explore the potential of chromium phosphonates as direct lithium extraction (DLE) adsorbents. To achieve optimal Li+ uptake capacity and selectivity, DLE adsorbents were designed to incorporate a Li+ favorable ’pocket’, templated during synthesis, along with a specific pore aperture for Li+ sieving. The study investigates the influence of pH, contact time, and concentration on adsorption, indicating a pseudo-second order kinetic model and monolayer chemisorption. Durability tests reveal these adsorbents maintain consistent uptake capacity and high stability.
dc.identifier.citationZhang, J. (2024). Proton conduction and lithium extraction in chromium (III) phosphonate metal-organic frameworks (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.urihttps://hdl.handle.net/1880/118100
dc.identifier.urihttps://doi.org/10.11575/PRISM/42944
dc.language.isoen
dc.publisher.facultyGraduate Studies
dc.publisher.institutionUniversity of Calgary
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectProton conduction
dc.subjectLithium extraction
dc.subjectMetal-organic frameworks
dc.subjectChromium phosphonates
dc.subjectProton exchange membrane fuel cells
dc.subject.classificationMaterials Science
dc.titleProton Conduction and Lithium Extraction in Chromium (III) Phosphonate Metal-Organic Frameworks
dc.typedoctoral thesis
thesis.degree.disciplineChemistry
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameDoctor of Philosophy (PhD)
ucalgary.thesis.accesssetbystudentI do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.
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