A novel laboratory setup for combined operando X‐ray diffraction and Raman spectroscopy of catalytic solids with online product analysis by gas chromatography is presented. The setup can be used with a laboratory‐based X‐ray source, which results in important advantages in terms of time‐on‐stream that can be measured, compared to synchrotron‐based experiments. The data quality was much improved by the use of a relatively high‐energy MoKα radiation instead of the more conventional CuKα radiation. We have applied the instrument to study the long‐term deactivation of Co/TiO2 Fischer–Tropsch synthesis (FTS) catalysts. No sign of Co sintering or bulk oxidation was found during the experiments. However, part of the metallic Co was converted into cobalt carbide (Co2C), at elevated pressure (10 bar). Furthermore, graphitic‐like coke species are clearly formed during FTS at atmospheric pressure, whereas at elevated pressure fluorescence hampered the interpretation of the measured Raman spectra.

Transmission X-ray microscopy has been used to investigate individual Co/TiO2 Fischer-Tropsch (FT) catalyst particles in 2-D and 3-D with 30 nm spatial resolution. Tomographic elemental mapping showed that Co is heterogeneously concentrated in the centre of the catalyst particles. In addition, it was found that Co is mostly metallic during FT at 250 °C and 10 bar. No evidence for Co oxidation was found.

The authors acknowledge financial support from The Dow Chemical Company. The Stanford Synchrotron Radiation Lightsource (SSRL) is supported by the US Department of Energy, Office of Basic Energy Sciences. We wish to thank to A. van der Eerden (Utrecht University) for his help with the design of the reactor cell. We further acknowledge P. Williams and T. Kao (SSRL) for their help during the data processing and R. Marks (SSRL) for the setting up of the gas flow system.Supporting information for this article is available on the WWW under http://dx.

A new combination of three chemical imaging methods has been developed and applied to fresh and spent co-based Fischer–Tropsch catalysts.