Heiko Oosterbeek

Bridging the pressure and material gap in heterogeneous catalysis: cobalt Fischer–Tropsch catalysts from surface science to industrial application

The Fischer-Tropsch (FT) process is the heart of many natural gas conversion processes as it enables the conversion of a mixture of CO and H(2) into valuable long-chain hydrocarbons. Here we report on the use of state-of-the-art surface science techniques to obtain information on the relationship between the surface atomic structure of model catalysts and their performance in the Fischer-Tropsch reaction. Cobalt single crystals and polycrystals were modified with non-reducible oxides as to resemble industrial catalysts. Reflection absorption infrared spectroscopy was used for examining the CO adsorption behaviour at room temperature as well as at 493 K at CO pressures spanning 10(-7) to 300 mbar on both (modified) Co single/polycrystals and an industrial catalyst. Polarization modulation was applied to cancel the CO gas phase absorption. Subsequently, they were subjected to reaction tests in the same apparatus at 1 bar and 493 K. This allowed us to close the material, pressure and instrument gap in the field of Fischer-Tropsch synthesis on cobalt-based catalysts.

REFLECTION-ABSORPTION INFRARED SPECTROSCOPIC STUDY ON A CUOX/SIO2 MODEL CATALYST PREPARED BY SPIN-COATING ON A SIO2/W/SI(100) BURIED METAL SUBSTRATE

Abstract CuO X particles were deposited by spin-coating on a SiO 2 (50 nm)/W(70 nm)/Si(100) buried metal substrate using 2-propanol solution of a Cu precursor followed by oxidation. The CuO X /SiO 2 /W/Si model catalyst was used to detect vibrational modes of submonolayer adsorbates by reflection–absorption infrared spectroscopy (RAIRS). During methanol reaction on CuO X /SiO 2 /W/Si, RAIR spectra showed that methoxy species was formed on CuO X particles and spilt over to the SiO 2 substrate, replacing hydroxyl species.