Matt Darby

Matthew studied at the University of Bristol from 2009 until 2013 and was awarded with a first class MSci in Chemistry. His final year focused on the development and implementation of a new wavepacket method for quantum dynamics. Having joined UCL in autumn 2013, Matthew is now using ab initio kinetic Monte Carlo simulation to study hydrogenation reactions on bimetallic catalysts. .

Research project

Title: Ab Initio Kinetic Monte Carlo Simulations of Hydrogenation Reactions on Bimetallic Catalysts.

The heterogeneous catalysis of hydrogenation reactions plays a significant role within numerous areas such as the petrochemical, pharmaceutical and food industries. Precious metals including Pt, Pd and Ru are often employed as hydrogenation catalysts owing to their high reactivity towards hydrogen. Using such metals on a commercial scale can prove costly and so cheaper alternatives are being sought after.

Experiment has shown that doping a less reactive, cheaper host metal such as Cu, with a low concentration of a more reactive metal, such as Pd, increases the surface reactivity towards hydrogen with respect to the pure host metal [1]. The dopant metal provides a low energy pathway for hydrogen dissociation and facilitates spillover onto the host metal. Furthermore, control over the spillover, and hence the surface coverage, may be established through the selective binding of a spectator CO molecule at the minority metal site. The low energy pathway is selectively blocked, inhibiting hydrogen dissociation and re-association, thus trapping hydrogen on the surface; this phenomenon has been termed the ‘molecular cork effect’ and may have implications in mediating the kinetics of hydrogen uptake in bimetallic catalysis. Though observed in experiment the underlying cause of the molecular cork effect remains a mystery [2].

Using modern day computational techniques such as density functional theory (DFT) and kinetic Monte Carlo (KMC) we can provide valuable insight into unknown mechanisms behind many phenomena such as the molecular cork effect whilst aiding in the design and discovery of improved hydrogenation catalysts.

Education

MSci in Chemistry, University of Bristol, 2013