The University of Bath is inviting applications for a funded PhD project under the supervision of Dr Alexander O’Malley https://researchportal.bath.ac.uk/en/persons/alexander-omalley
in the Department of Chemistry https://www.bath.ac.uk/departments/department-of-chemistry/
OVERVIEW OF THE RESEARCH:
The demand for sustainable chemicals and fuels has led to significant research into finding alternative feedstocks to bypass crude oil. Of these, the zeolite catalysed methanol-to-hydrocarbons (MTH) process is a prominent technology for olefin production in particular, as methanol can be produced from a wide range of carbon-containing sources e.g. biomass, plastic waste or even carbon dioxide.
While MTH mechanism is highly disputed, other important components such as the mobility of the initial active species (methanol and dimethylether (DME)) remain mostly unstudied. This is partly because of the changing nature of the zeolite catalyst as the reaction progresses. It is widely believed that reaction proceeds via a ‘pool’ of hydrocarbons (consisting mainly of alkenes/aromatics) within the zeolite pores. How this pool is formed and its role in the catalyst deactivation are not so well understood, mainly due to the difficulty of determining which species are present, or indeed mobile during the reaction.
Despite numerous in-depth mechanistic studies, fundamental knowledge of molecular mobility as a function of zeolite framework topology, composition (Si/Al ratio), the presence of other species, defect presence due to framework destruction, and pore blockage due to ‘coking’ remains poorly understood. This is particularly true in terms of multiscale studies, where the local/molecular scale (i.e. < 10 angstroms from the active site), the nanoscale (probing mobility through the framework structure) and the microscale (measuring mass transport across entire particles) can present significant challenges.
The studentship will answer the following questions:
1) How does the multiscale methanol/DME mobility change across a variety of zeolite catalyst frameworks and Si/Al ratios? Can these changes be linked with activity?
2) How does the presence of aromatic compounds featuring in the hydrocarbon pool affect methanol/DME mobility in differing zeolite frameworks?
3) How does catalyst deactivation due to framework damage and pore blockage affect the mobility of the initiation species, is this linked to a loss in catalytic activity?
The aforementioned scales will be probed as follows:
- Motions local to the zeolite active site will be probed with vibrational spectroscopy (using infrared/neutrons) paired with DFT (both static and dynamic) simulations.
- Molecular mobility through each different zeolite framework on the nanoscale will be studied with quasielastic neutron scattering and classical molecular dynamics (CMD) simulations.
- Mass transport and inter-/intracrystalline diffusion studies on the microscale would employ pulsed field gradient NMR and gravimetric sorption.
Applicants should hold, or expect to receive, a First Class or high Upper Second Class UK Honours degree (or the equivalent qualification gained outside the UK) in Chemistry, Chemical Engineering, Physics, Materials or related disciplines. A master’s level qualification would also be advantageous. Non-UK applicants must meet our English language entry requirement http://www.bath.ac.uk/study/pg/apply/english-language/index.html
ENQUIRIES AND APPLICATIONS:
Informal enquiries are welcomed and should be addressed to Dr Alexander O’Malley, email [email protected]
Formal applications should be made via the University of Bath’s online application form for a PhD in Chemistry: https://samis.bath.ac.uk/urd/sits.urd/run/siw_ipp_lgn.login?process=siw_ipp_app&code1=RDUCH-FP01&code2=0014
Please ensure that you quote the supervisor’s name and project title in the ‘Your research interests’ section.
More information about applying for a PhD at Bath may be found here: http://www.bath.ac.uk/guides/how-to-apply-for-doctoral-study/
Anticipated start date: 28 September 2020.
Note: Applications may close earlier than the advertised deadline if a suitable candidate is found; therefore, early application is recommended.
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