Measuring diffusion of small molecules in heterogeneous catalysts

In a new collaboration with the University of Glasgow, Johnson Matthey are sponsoring an EPSRC Industrial CASE Ph.D. studentship to use a combination of (i) reaction testing, (ii) optical spectroscopy, (iii) electron microscopy and (iv) quasi-elastic neutron scattering (QENS) to investigate fundamental aspects of catalytic events in high surface area heterogeneous catalysts.

QENS is a powerful technique for measuring diffusion in solids. On occasion, it has been used for studying catalytic systems, principally with zeolites, but the database is not large. Given recent advances in the application of inelastic neutron scattering to investigate heterogeneous catalysts and the associated development of sample environment to support that work, it is now timely to extend those investigations to include a diffusional component via application of QENS. Such studies will provide new information on the following fundamental areas: interference phenomena between atoms, lattice distortions of the zeolite, short-range order, atoms or molecules experiencing stochastic motions, etc.

Understanding how molecules diffuse within heterogeneous catalysts is of great importance to a number of diverse processes, such as selective catalytic reduction, methanol synthesis and CO2 capture. The general area of diffusion also connects to the disciplines of process technology and emission control technology. The development of the QENS technique for assessing diffusion of species in working catalysts/materials is novel and will provide an improved understanding of reaction kinetics, which can then be linked to catalyst performance. The student will be primarily located at the Harwell Research Complex, which is located at the Rutherford Appleton Laboratory in Oxfordshire. In addition, each year, the student will be expected to spend a placement at one of the Company's UK research centres.