Multiple and antagonistic effects of water on intrinsic physical properties of model Fischer-Tropsch cobalt catalysts evidenced by in situ X-ray diffraction.

Direct evidence for cobalt oxidation under water treatment at 230 °C was revealed using in situ XRD, even in the presence of small amounts of H2. Oxidation kinetics was proved to be particle size dependent. The resulting Co3O4 showed a firmly smaller coherent domain size than the initial calcined catalyst.