Here we investigate the oxidation of Co(OH)2 using the catalysis cell. The catalysis cell allowed us to treat the sample under high temperature high pressure conditions similar to those found in industrial reactors. Careful analysis of the XPS spectra generated after each successive treatment shows that once calcined above 200 ÂșC the surface of the catalyst changes from hydroxide to oxide. Peak fitting the Co 2p region identified Co to be present as Co3O4.