Combining Frustrated Lewis Pair (FLP) and Solid State Molecular Organometallic (SMOM) Catalysis

Lead Research Organisation: University of Oxford
Department Name: OxICFM CDT

Abstract

This project falls within the EPSRC "Manufacturing the future" research theme, with a focus on catalysis.
Performing chemical processes, such as making plastics and refining fuels, takes a great deal of energy. Catalysts reduce this energy requirement and, in some cases, allow these processes to happen at all. Current catalyst technology is based on precious metals, such as platinum and palladium. These are not only expensive but display toxicity towards humans and the environment. When designing future catalysts we must move away from the expensive and toxic precious metals and move towards more sustainable elements.
My work focuses on using non-metals, such as phosphorus and boron, from the p block of the periodic table to perform catalysis. In order to move away from traditional metal-based catalyst systems I will use bulky Lewis acid and base systems to perform metal free catalysis. Lewis bases are compounds with a lone pair of electrons and Lewis acids are compounds that accept a lone pair of electrons. When a Lewis acid and base are brought together an adduct normally is formed from the lone pair on the Lewis base being donated to the Lewis acid. However, in a frustrated Lewis pair (FLP), bulky Lewis acids and bases prevent adduct formation leading to a system which can donate and accept electrons much like traditional metal catalysts. FLPs have been shown to be active hydrogenation catalysts, which is the process in which hydrogen atoms are added to a compound. These systems are not used widely in industry due to lower activity than the current metal-based systems and lack of compatibility with industrial chemistry. The purpose of this project is to develop a FLP system that may be compatible with, and, provide activities that rival the current industrial processes.
Much of the current work in this field is done in solution with reactants, products and catalyst all being dissolved in solution and thus being in the same phase. This is described as a homogenous system; however, the unique aspect of my research is heterogenous reactivity. This means using a solid catalyst with reactants and products that are either in the gas or solution phase. The catalyst existing in a different phase allows for continuous reactivity as reagents flow across the catalyst, rather than having to work in batches. This allows for no down time between batches, increasing the efficiency of the process. Further to this, no additional separation of the catalyst, reactants and products is required. These factors together save on cost and energy, with benefits to both the consumer and the environment. In order to achieve heterogenous catalytic activity I will be employing the solid-state molecular organometallic (SMOM) approach used by Prof. Weller et al. using a BArF anion, a bulky negatively charged ion, to facilitate reactivity of the FLP as a single crystal. Through my project I will be collaborating with Prof Weller at the University of York.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S023828/1 01/04/2019 30/09/2027
2329320 Studentship EP/S023828/1 01/10/2019 30/09/2023 Agamemnon Crumpton