An alumina-supported nickel catalyst has been used to effect the 'dry' reforming of methane, using CO(2) as the oxidant. After 6 hours on-stream, reaction was stopped and the sample analysed by inelastic neutron scattering (INS). The INS spectrum reveals the presence of hydrocarbonaceous species as well as hydroxyl species present at the catalyst surface. Through the use of appropriate reference compounds, calibration procedures have been developed to determine the concentration of the retained hydrocarbon and hydroxyl moieties. Ancillary temperature programmed oxidation experiments establish the total carbon content. This approach not only enables the extent of overall carbon laydown to be determined but it also identifies the degree to which hydrogen is associated with carbon and oxygen atoms. The methodology described is generic and should be applicable to a wide number of heterogeneously catalysed systems.