Controlled routes to aluminium-containing alloys from molecular precursors

A number of important chemical processes are electrolytic, meaning that they are driven by passing electricity through the reaction mixture. Often, materials which increase the rate of these processes (electrocatalysts) are used to improve the energy efficiency and capacity of the process, but these materials commonly contain so-called 'noble metals' such as palladium or iridium. Noble metals are scarce and expensive, and so it can be challenging to carry out these processes at the large scales required industrially. One such process is the electrolytic conversion of water to hydrogen and oxygen. Hydrogen gas is an important product due to its viability as a 'green' fuel, and so its efficient production is becoming ever more crucial as we seek to move away from traditional carbon-based fuels. It is therefore necessary to find effective new electrocatalysts which contain cheaper and more abundant metals so that hydrogen production may more easily be carried out at the large scales required.
One potential class of materials are alloys (metals containing a mixture of elements) of aluminium (the most abundant metal in the earth's crust) with base metals (such as iron or manganese). These alloys are challenging to synthesise due to aluminium's very low melting point, so alternative routes are required. One option is to synthesise molecular compounds containing an Al-M bond which decompose at high temperatures to form the desired alloy. Such compounds (referred to as Single Source Precursors or SSPs) allow us to generate otherwise inaccessible materials.
One challenge this approach poses is in finding a systematic means of synthesising a range of Al-M bonded compounds for a variety of metals. Such compounds exist for a few select metals, but their syntheses isn't readily generalisable (so fewer possible electrocatalyst materials can be made and tested), and the Al-M bonds are often weak, so they may not be suitable for thermal generation of an alloy. The recent discovery of a new class of compound, aluminyls, which feature an anionic (negatively charged) aluminium atom supported by an organic scaffold, offers a solution. This type of compound is suitable for reaction with a large range of other metal compounds, and so offers a general route to a wide range of SSPs containing strong (covalent) Al-M bonds.
The aim of this project is therefore to use these aluminyl compounds (and potentially related gallium and indium analogues) to synthesise a broad library of SSPs containing a variety of base metals. These compounds will be studied to provide insight into their chemical behaviour, before exploring their conversion into aluminium containing alloys by thermal decomposition. These alloys will be analysed to determine their exact composition and surface structure, and finally tested as electrocatalysts to compare their performances with those of traditional noble metal materials.
The use of aluminyl and related systems as a means of accessing this class of compound, as well as their subsequent conversion into potentially active alloys, is a novel approach within this field.
This project falls within the EPSRC manufacturing the future research area.
This project will involve collaboration with both the Moody group from the Department of Materials at the University of Oxford (for the analysis and characterisation of alloy material) and with the Driess group from the Department of Chemistry at TU Berlin for the investigation of electrocatalytic activity.

The primary impact of the OxICFM CDT will be the highly-trained world-class scientists that it delivers. This impact will encompass both the short term (during their doctoral studies), the medium term (subsequent employment) and ultimately the longer timescale defined by their future careers and consequent impact on science, engineering and policy in the UK.

The impact of OxICFM students during their doctoral studies will be measured by the culture change in graduate training that the Centre brings about - in working at the interface between inorganic synthesis and manufacturing, and fostering cross-sector industry/academia working practices. By embedding not only from larger companies, but also SMEs, we have developed a training regime that has broader relevance across the sector, and the potential for building bridges by fostering new collaborations spanning enormous diversity in scientific focus and scale. Moreover, at a broader level, OxICFM offers to play a unique role as a major focus (and advocate) for manufacturing engagement with academic inorganic synthetic science in the UK.

From a scientific perspective, OxICFM will be uniquely able to offer a broad training programme incorporating innovative and challenging collaborative projects spanning all aspects of fundamental and applied inorganic synthesis, both molecular and materials based (40+ faculty). These will address key challenges in areas such as energy provision/storage, catalysis, and resource provision/renewal necessary to enhance the capability and durability of UK plc in the medium term. To give some idea of perspective, the output from previous CDTs in Oxford's MPLS Division include two start-up companies and in excess of 30 patents.

It is not only in the industrial and scientific realms that students will have impact during their timeframe of their doctorate. Part of the training programme will be in public engagement: team-based challenges in resource development/training and outreach exercises/implementation will form part of the annual summer school. These in turn will constitute a key part of the impact derived from the CDT by its engagement with the public - both face-to-face and through electronic/web-based media. As the centre matures, our aspiration is that our students - from diverse backgrounds - will act as ambassadors for the programme and promote even higher levels of inclusion from all parts of society.

For our partners, and businesses both large and small in the manufacturing sector, it will be our students who are considered the ultimate output of the OxICFM CDT. Our programme has been shaped by the need of such companies (frequently expressed in preliminary discussions) to recruit doctoral graduates who can apply themselves to a broad spectrum of multi-disciplinary challenges in manufacturing-related synthesis. OxICFM's cohort-based training programme integrates significant industry-led training components and has been designed to deliver a much broader skill set than standard PhD schemes. The current lack of CDT training at the interface of inorganic chemistry and manufacturing (and the relevance of inorganic molecules/materials to numerous industrial sectors) heightens the need for - and the potential impact of - the OxICFM CDT. Our students will represent a tangible and valuable asset to meet the long-term skills demand for scientists to develop new materials and nanotechnology identified in the UK Government's 2013 Foresight report.

In the longer term, the broad and relevant training delivered by OxICFM, and the uniquely wide perspective of the manufacturing sector it will deliver, will allow our graduates to obtain (and thrive in) positions of significant responsibility in industry and in research facilities/institutes. Ultimately we believe that many will go on to be future research leaders, driving innovation and changing research culture, and thereby making a lasting contribution to the UK economy.