The applicants have recently completed a series of INS studies on a model iron Fischer-Tropsch catalyst. That work established that different sample pre-treatments could significantly affect ultimate catalytic performance. Moreover, the INS spectrum appeared to be diagnostic for the active phase of the catalyst. That work is currently being prepared for publication. This work seeks to extend those studies to examine a reference iron catalyst plus an industrial specification catalyst that contains a chemical promoter. These new studies will establish the usefulness of INS to characterise prototype catalysts for this economically important reaction.