Tailoring surfaces in heterogeneous catalysis for fine chemical production

Heterogeneous catalysis is of great importance and is, rightly so, amongst the most widely researched fields in the scientific community. However, there is a clear lack of knowledge and understanding of how the interactions between a catalyst surface and molecules in the system work and govern the activity and selectivities seen in these reactions.

Furthermore, the role of the active metal in heterogeneous catalytic systems is commonly investigated with relatively much less attention being paid to the role of the support. The catalyst support has a large influence on catalytic systems so it is vital that the interactions of the support with the rest of these systems are understood. Modifications to catalyst supports have proved to be of great value in optimising catalytic reactions and by gaining a greater understanding of how reactants and products interact with the surface, these modifications can be fine-tuned and utilised to give far more efficient catalysts with unlimited potential.

Finally, the role of the solvent clearly plays a large part in designing efficient catalytic systems and only by investigating how solvent molecules interact with the surface of the catalyst can we learn to utilise this.

Nuclear magnetic resonance (NMR) spectroscopy, relaxation and pulsed field gradient (PFG)-NMR are powerful techniques to aid the design of heterogeneous catalysts, their characterisation, and their deactivation. Using NMR to study catalysis can provide valuable information to aid the design of more active and efficient catalytic systems.

The molecular dynamics of reactants and solvents interacting with the catalyst surface continue to be of great importance to the design of heterogeneous catalytic systems and these interactions are something that can be simply and effectively studied by NMR techniques. Indeed, it has been shown that NMR relaxation time measurements can be used to characterise the adsorption strengths of reactants with the catalyst surface.

(PFG)-NMR and NMR relaxation measurements can be used to characterise and probe the effects of modifications upon a surface upon the adsorption of reactants. By measuring the diffusivity of guest molecules within the pore network of heterogeneous catalytic materials it is possible to simply investigate the mass transport processes occurring within the catalyst pores which determine a catalytic reactions reactivity and selectivity.

Low field NMR techniques will be used to investigate adsorption and diffusion process within porous materials during the length of this project. In addition to this, porous materials will be functionalised using novel functionalisation techniques or the pore structures of porous materials will be altered. Finally, catalytic testing (namely hydrogenation reactions in pressurised vessels) along with common solid state characterisation techniques (i.e. porosimetry, microscopy etc.) will be used to fully explain the catalytic materials reactivity and link all this information back to how we can influence the surface of the materials to produce more efficient catalytic systems.

Catalytic reactions are amongst the most common important class of reactions that take place in industry today and, as such, research into the development and improvement of these reactions is of great importance. Most of the current work in the area however, is focused on the role of the active metal and the effect of the catalyst support upon catalytic performance is much more poorly understood. The novelty of this work lies in the investigation of how we can alter a catalyst support to produce better, more efficient catalytic systems, something that up to know has been relatively poorly understood. Novel low field NMR techniques will be used to unravel the influence of the catalyst support.