Syngas (or synthesis gas) is a mixture of carbon monoxide and hydrogen, which can be converted into clean gasoline and diesel by a process called Fischer-Tropsch catalysis. Importantly the carbon monoxide can come from any carbon source including biomass, coal and methane, so the process is very flexible. Sasol are pioneers and world leaders in this technology and their manufacturing plants in South Africa produce millions of litres of fuel a day, supplying about a third of the national demand. This massive scale of production relies on mastery of materials at the nanoscale. Scientists have been using ISIS to study Fischer-Tropsch catalysis at this molecular level, in order to better understand this vital process. The work was done in collaboration with Sasol Technology UK Ltd. and Glasgow University.
At the heart of the process is a catalyst, and iron-based catalysts are often used as iron is widely available. In the reactor the iron-based catalyst precursor transforms to the active catalyst in a highly complex system (see Figure 1). Amorphous carbon, metallic iron and carbides are all present, as well as a layer of hydrocarbon, and the role each plays in the catalysis process is believed to be critical.
The group first used the TOSCA instrument at ISIS to study samples from a working plant in South Africa to investigate the nature of the surface hydrocarbon layer . This is very difficult to study by conventional methods, but is possible with neutron spectroscopy, which is able to characterise hydrogen-containing species. This is the first time the technique has been used to examine the Fischer-Tropsch process on a real industrial catalyst . Follow-up work has examined how the iron-based catalysts respond to different reaction conditions .
Research date: April 2014
 Vibrational Analysis of an Industrial Fe-based Fischer-Tropsch Catalyst Employing Inelastic Neutron Scattering, N.G. Hamilton, I.P. Silverwood, R. Warringham, J. Kapitán, L. Hecht, P.B. Webb, R.P. Tooze, S.F. Parker and D. Lennon, Angewandte Chemie International Edition, 52 (2013) 5608-5611.
 The application of inelastic neutron scattering to investigate CO hydrogenation over an iron Fischer-Tropsch synthesis catalyst, N.G. Hamilton, R. Warringham, I.P. Silverwood, J. Kapitán, L. Hecht, P.B. Webb, R.P. Tooze, W. Zhou, C.D. Frost, S.F. Parker and D. Lennon, Journal of Catalysis, 312 (2014) 221-231.