Microporous metal oxides for the oxidation of alkanes to primary alcohols

The development of novel catalysts for selective oxidation reactions is an area of decisive importance for both industry and academia. In fact, there is a major need for: (i) catalysts capable of delivering energy-efficient processes with enhanced selectivity to a desired product and (ii) oxidation routes that make use of air (molecular oxygen) for greener manufacturing processes. To achieve these results, this proposal will develop novel structured microporous metal oxides to use as catalysts.

These novel materials will be targeted to the synthesis of primary alcohols from alkanes using molecular oxygen as oxidant. Primary alcohols play a crucial role in chemistry, as they are essential building blocks for the pharmaceutical, food additives and cosmetics industries. However, a full range of primary alcohols is difficult to obtain synthetically, or to extract from natural sources.

All of the current catalysts for alkane oxidation lack control of selectivity to a desired alcohol product, with the exception of a few bacteria capable of catalytic monohydroxylation. These can selectively functionalise C-H bonds at the end of a hydrocarbon chain without attacking more reactive C-H bonds within the carbon chain. Therefore, a new paradigm for selective oxidation of alkanes to primary alcohols is necessary and would be of immense importance. In fact, this would also convert alkanes from a non-renewable fossil fuel source into a useful chemical synthesis feedstock. Thus these new microporous metal oxides will deliver shape-selective control of reactivity combined with redox chemistry, as in enzymatic systems.

This project will also investigate the fundamental catalytic mechanisms using an array of spectroscopic tools including X-ray photoelectron spectroscopy and electron paramagnetic resonance, as well as X-ray diffraction methods. These insights will deliver a new alcohol manufacturing technology that will be of benefit for the UK industry, as well as the design of materials that will impact areas beyond catalysis, e.g. materials science, spectroscopy, biomimetic synthesis and chemical engineering.

The impact of this proposal will affect: industry and economy, society and general public, the academic community within and beyond catalysis, and the possible training of PhD students.

Industry and economy.
There is a current gap in the UK for processes to manufacture primary alcohols. At present all of the patent holders for such processes are based in the US, for a market with productivity in excess of 2M tonne per year. Therefore a clear benefit to the UK industry can arise, e.g. for catalyst manufacturers and users of primary alcohols in the cosmetics, drugs and food sectors. This project will exploit the strong tradition in catalyst preparation from UK industries which can provide a platform for the commercialisation of these products with a benefit for the UK economy.

Increasing benefit to Industrial sectors from translational working with the Academic community.
The academic community will benefit from this project and in areas within and beyond catalysis. In fact, beside applications in heterogeneous catalysis, benefits will also be present for: (i) materials science, (ii) biomimetic synthesis, (iii) spectroscopy (XPS and EPR) and (iv) chemical engineering (see academic beneficiaries document and academic impact sections).

Society and general public.
By carrying out direct monohydroxylation of hydrocarbons to alcohols, this project will convert hydrocarbons into useful chemical synthesis feedstocks rather than using them as non-renewable fossil fuel. Moreover, as the catalysts at the centre of this proposal are aimed to obtain specific products by using oxygen or air as oxidizing agent, this will provide greener manufacturing processes capable of a more efficient energy cost, as well as a reduced carbon foot print, which are both strategic targets in the UK political agenda. Additionally, the primary alcohols that are the products of this research project find use as: drug precursors, food additives, moisturizing agents and preservatives. Hence these final products will be accessible at a lower cost.

Student training.
This scheme is not designed to the recruitment of PhD students, yet if this application is successful the host institution (University of Sheffield) is committed to provide a PhD student for this project, and the collaborator (Leibniz Institute for Catalysis, Rostock, Germany) is committed to apply for a PhD studentship funded by this same institution. Due to the interdisciplinary nature of this project this would allow the training of students in possession of a wide range of experimental skills that will be useful to both industry and academia, ranging from catalyst preparation to spectroscopy.