Hydrogenation of CO2 over Co supported on carbon nanotube, carbon nanotube-Nb2O5, carbon nanofiber, low-layered graphite fragments and Nb2O5

Abstract

CO2 hydrogenation was studied with catalysts containing 1.5–35 wt% Co supported on carbon nanotubes, nanofibers, low-layered graphite fragments and composites of carbon nanotube-Nb2O5. All catalytic processes with Co/supported catalysts were investigated using XRF, DSC, TGA, H2-TPR, TEM, SEM and XPS. Based on obtained results, it is indicated that the products from CO2 hydrogenation were CH4 and/or CO under reaction conditions pressure of 1.5 MPa and temperature of 200–500 °C, as well as the size of the particles of Co and their phase state directly affected on the catalysts activity. 3 wt% Co catalyst supported on carbon nanotubes has shown catalytic inactivity due to amorphous state of metal. It is possible to activate them during Co crystallization after thermal treatment. It is shown, that the size of Co particles supported on carbon nanotubes is 4–6 nm. The methods of fictionalization the surface of carbon nanomaterials ensuring an additional stability of metal nanoparticles is recommended.