Spectroscopic investigation of a Co(0001) model catalyst during exposure to H and CO at near-ambient pressures.

Cobalt catalysts, although already used industrially for Fischer-Tropsch synthesis, are prone to a number of deactivation mechanisms such as oxidation of the active phase, and the deposition of carbon and reaction products. We have performed near-ambient-pressure X-ray photoelectron spectroscopy on Co(0001) model catalysts during exposure to gases relevant to Fischer-Tropsch synthesis, , CO and H, at 0.25 mbar total pressure.

Structural Characterization of a Novel Two-Dimensional Material: Cobalt Sulfide Sheets on Au(111).

Transition metal dichalcogenides (TMDCs) are a type of two-dimensional (2D) material that has been widely investigated by both experimentalists and theoreticians because of their unique properties. In the case of cobalt sulfide, density functional theory (DFT) calculations on free-standing S-Co-S sheets suggest there are no stable 2D cobalt sulfide polymorphs, whereas experimental observations clearly show TMDC-like structures on Au(111). In this study, we resolve this disagreement by using a combination of experimental techniques and DFT calculations, considering the substrate explicitly.