Metal Nanoparticle - MOF Templates; Tailored Routes to Controlled Nanocomposites for Catalysis

Lead Research Organisation: University of Southampton
Department Name: School of Chemistry

Abstract

The drive towards more sustainable technologies relies on developing improved catalytic materials; greater activity and selectivity to desired products with ever decreasing amounts of expensive catalyst metals. Supported metal nanoparticles are a cornerstone within the field of heterogeneous catalysis; the metal support interaction aids the stability of the catalyst and promotes chemical reactions. Controlling the interface of composite structures is a key part of this synergy between metal nanoparticle and metal oxide support. Supported metal nanoparticles are most commonly prepared by the impregnation of metal oxide hosts, followed by a thermal activation. The concept of the project is to use metal nanoparticles supported on MOFs as templates. The intention is to remove the organic linkers through chemical means, i.e. by introducing strong reductants such as NaBH4, producing tailored nanocomposites. Indeed, we have recently performed a proof-of-concept study where we were able to prepare PdCu/Cu2O nanocomposites from Pd/Cu-BTC templates. The programme of work will:

(i) Show how systematic variations to preparation conditions influences the composite structure.

(ii) Demonstrate their importance for emerging catalytic applications in sustainable energy generation (i.e formic acid decomposition).

(iii) Use advanced characterisation under process conditions to understand the formation of the composite structure and how the structures evolve during catalysis.

Planned Impact

Catalysis can often be invisible to wider society but it underpins many aspects of our daily lives; even the food we eat is reliant upon nitrogen fixation through the Haber-Bosch process. The economic impact of catalysis is also of major importance to the UK; catalysis is a core area of the chemical industry and is already of significant value to the UK economy, generating over £50 billion annually. With global population rises, environmental concerns, and dwindling supplies of conventional energy resources there is a need to move towards sustainable technologies - not just for the distant future but for the present day. These technologies are going to be reliant on catalysts that are able to achieve 'more with less'; improved catalyst performance (activity, selectivity, durability) with a decrease in the amount of expensive metals used. This desire is going to rely on precision nano-engineering using innovative preparative routes which maximizes the number of the most highly active sites per unit mass. This project aims to pioneer a new method of preparing composites from metal nanoparticle-MOF templates. The societal impact will be how these materials are able to impact on sustainable technologies. Here, we have identified formic acid decomposition as an exemplar reaction, this is important for energy storage and a clean source of hydrogen; using renewable energy to produce formic acid allows the energy to be stored and subsequently harvested through the release of hydrogen. Moreover, the move towards a hydrogen as the major fuel source will decrease our reliance on fossil fuels and the environmental concerns linked to them e.g. air quality and climate change. Where breakthroughs in catalyst design allow new technologies to replace existing ones there is a significant economic impact; for example, infrastructure investment, catalyst manufacture, production plants, wider R&D landscape investment, and secondary supply chain growth will all boost the UK economy and he prosperity of the nation. In the timescale (12 months) and resource level (1 year PDRA) of this project it is not realistic that substantial improvements can be made and implemented into commercial solutions. However, the landscape into which this work fits and impact it is directed towards has been outlined.

Publications

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Description We have developed a new chemical method for preparing metal - metal oxide nanoparticles for applications in heterogeneous catalysis.

We have developed how the strucural properties of these materials can be fine-tuned by adjusting the conditions in which they are made.
Exploitation Route There are two clear ways to take this work forward:

1) Further heterogeneous catalysis studies
2) Expand the scope of the materials produced to other metal-metal oxide composites.
Sectors Chemicals,Energy