Operando Analysis of Industrially Relevant Rh-P catalysed Olefin Hydroformylation by Multi-Nuclear FlowNMR Spectroscopy

In this project we will use operando FlowNMR as a tool to gain unprecedented levels of insight into hydroformylation catalysis mediated by rhodium-phosphine complexes. Although olefin hydroformylation is a well-established technology and with >10 Mt p.a. one of the largest homogeneously catalysed processes in the world, there still are many application-relevant questions around the origin of chemo-, regio- and enantioselectivity as well as dormant and deactivated catalyst species leading to the formation of unwanted side-products in this chemistry. This is particularly true for some of the more 'unusual' phosphines such as Evonik's bulky phosphonites and bis-phosphites and as well as Eastman's fluoro-phosphites that give high levels n-selectivity under surprisingly mild conditions. Understanding how and why they differ from the classical aryl-phosphine Wilkinson systems promises access to design principles that will allow the development of improved systems that be tailored to a desired product selectivity, and thus form the basis of new, cleaner and more efficient hydroformylation processes.
We will use Bath's unique capabilities in operando FlowNMR spectroscopy to follow catalyst activation, turnover, and recovery & reuse by rapid and quantitative in-situ 1H, 19F and 31P FlowNMR. Multi-dimensional correlation spectroscopy, selective decoupling, hetero-nuclear diffusion analysis and polarisation transfer experiments in conjunction with selective excitation of low intensity signals will give a comprehensive picture of catalyst speciation that may be directly correlated with the overall reaction progress. A particular focus will lie on identifying pathways that lead into dormant species, irreversible deactivation and unwanted side-product formation, all important considerations for large-scale application. Spectral traces will be analysed by Reaction Progress Kinetic Analysis (RPKA) using Variable Time-Normalization (VTN) to establish solid kinetic descriptors for all relevant parameters describing the behaviour of the catalytic system.

Catalysis is crucially important to the UK economy, with products and services reliant on catalytic processes amounting to 21% of GDP and 15% of all exports. The UK is scientifically strong and internationally recognised in the field, but the science base is fragmented and becoming increasingly specialised. The EPSRC Centre for Doctoral Training in Catalysis will overcome these problems by acting as beacon for excellent postgraduate training in Catalysis and Reaction Engineering with a programme that will develop an advanced knowledge base of traditional and emerging catalysis disciplines, understanding of industry and global contexts, and research and professional skills tailored to the needs of the catalysis researcher.

Although the chemical sector is an immensely successful and important part of the overall UK economy, this sector is not the only end-user of catalysis. Through its training and its research portfolio the Centre will, therefore, impact on a broad range of technologies, processes and markets. It will:
(a) provide UK industry with the underpinning science and the personnel from which to develop and commercially leverage innovative future technologies for the global marketplace;
(b) allow the UK to maintain its position as a world leader in the high-technology area of catalysis and reactor engineering;
(c) consolidate and establish the UK as the centre for catalysis expertise.

Likewise, society will benefit from the human and intellectual resource that the Centre will supply. The skills and technologies that will be developed within the Centre will be highly applicable to the fields of sustainable manufacture, efficient and clean energy generation, and the protection of the environment through the clean-up of air and water - allowing some of the biggest societal challenges to be addressed.