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Projects: Projects for Investigator
Reference Number EP/W015552/1
Title "In-Crystallo" Solid-State Molecular Organometallic Chemistry of Methane, Ethane and Propane. Synthesis, Structures and Catalysis in Single-Crystals
Status Started
Energy Categories Not Energy Related 95%;
Energy Efficiency(Industry) 5%;
Research Types Basic and strategic applied research 100%
Science and Technology Fields PHYSICAL SCIENCES AND MATHEMATICS (Chemistry) 50%;
ENGINEERING AND TECHNOLOGY (Chemical Engineering) 50%;
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Dr A Weller
No email address given
Oxford Chemistry
University of Oxford
Award Type Standard
Funding Source EPSRC
Start Date 01 July 2022
End Date 30 June 2025
Duration 36 months
Total Grant Value £526,463
Industrial Sectors Chemicals; Pharmaceuticals and Biotechnology
Region South East
Programme NC : Physical Sciences
 
Investigators Principal Investigator Dr A Weller , Oxford Chemistry, University of Oxford (100.000%)
  Industrial Collaborator Project Contact , SCG Chemicals Co. Ltd, Thailand (0.000%)
Web Site
Objectives
Abstract The simple, light, hydrocarbons methane (CH4), ethane (H3CCH3) and propane (H3CCH2CH3) are abundant natural resources. For example it has been estimated that there are approximately 200 Trillion m3 of methane reserves world-wide. As manufacturing feedstocks for the essential chemicals and materials that modern humankind needs simple hydrocarbons offer immense potential. However, while it has been estimated that over 95% (by weight) of organic chemicals in use come from adding value to (i.e., valorisation of) a small pool of simple hydrocarbon precursors, only 3% of current production is actually used for chemical manufacturing. The remaining 97% is simply burnt for its calorific value (e.g. transportation) or flared off - both being an incredible waste of a natural resource and also a significant contributor to climate change (CO2 emissions) or erosion of air quality. The increasing availability of bio-methane, and the shift to "non-conventional" shale gas, places even more importance on efficient light alkane valorisation for "net zero" carbon sustainability. This mismatch between the abundance and the potential of light alkanes is a significant fundamental scientific challenge and a huge technological opportunity. At its heart, the challenge of converting these feedstocks is one of catalysis, in which the perfect catalyst activates a specific C-H bond at low temperatures with 100% conversion to a desired product. Herein lies the challenge, as alkanes are some of the very poorest, and least reactive, ligands known. This means forming the key encounter complex, that precedes C-H activation, between the catalyst (nearly always metal-based) and the alkane is very challenging. Simply put, if this complex does not form, then C-H activation does not take place and the valuable chemical transformation that we want to perform on the alkane does not happen. This is a so-called "pre-equilibrium" problem. Such complexes between an alkane and a metal centre are called sigma-complexes and their synthesis using methane, ethane and propane lie at the heart of this proposal. While these problems can be overcome in an industrial setting by high temperatures and pressures using heterogeneous catalysts, this is energy inefficient and can lead to poor selectivity - leading to a downstream energy cost for product separation (it has been estimated that 10-15% of the world's total energy consumption is involved in chemical separations).We propose that this "pre-equilibrium" limitation can be overcome, as we have learned from biology, by controlling interaction of the substrate with not only the metal centre but also its immediate surrounding environment, the so-called secondary and tertiary coordination spheres. In this context, our proposal is to control, understand and utilise these interactions by performing synthesis, reactivity and catalysis entirely in the single crystal, rather than solution. While challenging, this removes the need for solvent (that outcompetes the alkane for binding to the metal) and immediately installs the secondary microenvironment around the active site that encourages alkane coordination. We will achieve this by a combination of "in crystallo" organometallic chemistry (pioneered by Weller) and calculations in the solid-state (usng Macgregor's expertise in computation) which harness the more diffuse interactions between the alkane substrate and the wider environment to both guide and maximise alkane binding. Once the ability to bind these simple alkanes at metal centres is established we will demonstrate our concept in an exemplar, but challenging, catalytic reaction that adds value to methane in an 100% atom efficient manner: the hydromethylation of propene.Our programme thus offers fundamental new opportunities to study the reactivity, and potential use in catalysis, of light alkanes, with a longer term vision for the efficient carbon-management of fossil- or bio-derived alkanes beyond simple burning.
Publications (none)
Final Report (none)
Added to Database 03/08/22