Hydrodesulfurization catalysts based on carbon nanostructures: A review

Current paper provides a comprehensive review of carbon nanostructure supported hydrodesulfurization (HDS) catalysts as well as serving as a guide to explore such compounds. In this venue, variety of such structures including activated carbon (AC), carbon black (CB), carbon black composite (CBC), carbon nanotubes (CNT) of single and multi-walled nature, carbon nanofibers (CNF), graphite, graphene as graphene oxide (GO) and reduced graphene oxides (rGO) and fullerenes have been discussed and their physiochemical properties have been provided. Moreover, a thorough comparison of the active phase distribution and catalyst morphology and the reaction pathways of carbon and commonly used γ-Al2O3 supports performed. This study further emphasizes upon the desirable weaker interactions between carbon based materials and the active metal phases as well as pore size distributions and specific surface area, which are all key factors leading to better HDS performance of such materials. Nonetheless, some shortcomings of these materials also mentioned. Ultimately, the effects of carbonaceous species on solubility, dispersion capabilities and chemical stabilities toward obtaining highly effective catalysts discussed.