Bean dregs-derived hierarchical porous carbons as metal-free catalysts for efficient dehydrogenation of propane to propylene

BACKGROUND Recently, nanocarbons (e.g. carbon nanotubes, nanodiamond and mesoporous carbon) were found to be efficient catalysts in dehydrogenation reactions. However, the preparation of these nanocarbons is costly, complicated and time-consuming. The goal of this study is to exploit a biomass-derived carbon for propane dehydrogenation. RESULTS Biomass-derived carbons with hierarchical porous structures and high surface area are prepared via carbonization of bean dregs with NaOH, and operated as metal-free catalysts for direct dehydrogenation of propane to propylene. The properties of the prepared carbon catalysts are characterized by SEM, TEM, XRD, N-2 sorption and XPS techniques, revealing the presence of many nanopores and oxygenated functional groups. The catalytic results show that the resultant carbons exhibit high catalytic activity, selectivity and stability for direct dehydrogenation of propane. The activation temperature can significantly affect the textural properties and surface functional groups of the carbons, and thus, affect their catalytic performance. CONCLUSION The excellent catalytic performance can be attributed to the high content of oxygenated functional groups combined with hierarchical porous structure and large surface area of the obtained porous carbons which could provide more accessible active sites. This work demonstrates the flexible utilization of bean dregs-derived carbons in propane dehydrogenation to propylene. (c) 2018 Society of Chemical Industry