Synthesis and Applications of Monolithic Metal-Organic Frameworks

Metal-organic frameworks (MOFs) are a diverse family of coordination polymers which result from the crystalline self-assembly of metal ions/oxide clusters with multi-dentate organic linkers. Despite outstanding academic results, these porous materials have not entered the industrial sphere; their powder morphology renders them unsuitable for most potential applications. A new class of monolithic MOF was recently reported - monolithMOF combine the single-crystal density and porosity of the theoretical MOF with the functionality of a pelletised material. Correspondingly, outstanding results were achieved for two MOFs, with monolithHKUST-1 (Cu3(benzene-1,3,5-tricarboxylate)2) setting a benchmark in natural gas storage while monolithZIF-8 (Zn(2-methylimidazolate)2) demonstrated a capacity to host catalytic nanoparticles, NP@monolithMOF, for practical and environmental water purification. With the aim of expanding on these preliminary results, the synthesis of new monolithic MOFs was explored. Zr-MOFs, renowned for their industrially favourable chemical, thermal and mechanical stability, were targeted. A synthetic procedure was developed for the preparation of the archetypal Zr-MOF UiO-66 (Zr6O4(OH)4(1,4-benzenedicarboxylate)6) as a robust and porous monolith, monolithUiO-66. A novel capacity to control bulk density and pore-size distribution in the macroscopic monolith, via the synthetic inclusion of non-crystalline mesoporosity, was also developed. The generality of this synthetic procedure towards Zr-MOFs in general was further explored including functionalised UiO-66 analogues as well as non- isostructural Zr-MOFs. The capacity of monolithMOFs to host nanoparticles was determined through analysis of the effects of nanoparticle surface functionality on doping level of monolithZIF-8. Subsequently, the immobilisation of mono-, bi- and tri-metallic nano-objects in monolithZIF-8 was pursued for a range of possible industrial applications. The more general capability of monolithic MOFs to host nanoparticles was determined via the synthesis of Pd@monolithHKUST-1. Finally, the feasibility of the new materials, monolithUiO-66 and Pd@monolithHKUST-1, towards possible industrial gas storage applications (CH4, CO2 and H2) was recorded. Benchmark volumetric CH4 and H2 storage capacities were collected in each monolith, and the dependence of these capacities on e.g. pore-size distribution and doping level were also elucidated. Overall, the synthesis of new monolithMOF and NP@monolithMOF composites was comprehensively explored, developing novel and practical materials for prospective industrial applications.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2020

Author dc:creator

• Connolly, Bethany

Advisor dc:contributor.advisor

• Wheatley, Andrew

• Chemistry
• Nanomaterials
• Gas Storage
• MOF

Licence

• https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/62241882-3369-4e69-b753-a87312ae16ca/download
• https://www.rioxx.net/licenses/all-rights-reserved/

Language dc:language

en

Author Identifier

0000-0002-4063-8071

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/300989