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

Abstract

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. These authors have made an equal contribution to this work.

Efficient Adsorption of Methylene Blue by Porous Biochar Derived from Soybean Dreg Using a One-Pot Synthesis Method

“…SEM and TEM characterized the porous structure. According to the SEM image ( Figure 1 a,b), the surface of the SD appeared as an irregular fold layered structure, which was relatively smooth and dense with no apparent pores [ 30 ]. However, after high-temperature activation with KHCO 3 , an abundance of pore structures was evident on the surface of the SDB-K-X, showing a 3D framework with randomly opened pores, indicating that KHCO 3 played a positive role in the pore formation of biochar.…”

Mesoporous carbons as metal-free catalysts for propane dehydrogenation: Effect of the pore structure and surface property

“…1. Therefore, almost no available active sites are accessible during the catalytic reaction [21,22]. MC-0-600 exhibits a very low catalytic activity in PDH (Fig.…”

“…Unlike oxidative dehydrogenation, direct dehydrogenation occurs in a condition without oxygen agents. In recent studies on carbon catalysts in direct dehydrogenation, the active sites and catalytic mechanisms are still not totally identified [18][19][20][21][22][33][34][35]. In general, defects, heteroatoms, and surface oxygenated functional groups are regarded as the active sites for direct dehydrogenation reaction.…”

“…All the surface oxygenated functional groups, defects, and heteroatom-derived groups make good contribution to the catalytic dehydrogenation. Moreover, biomass-derived carbon catalysts with rich oxygenated functional groups and high porosity are reported to exhibit high catalytic activity and stability in propane dehydrogenation (PDH) [21,22]. However, the catalytic mechanism and active sites of these carbon catalysts in the direct dehydrogenation of alkane have not been totally clarified owing to the lack of fundamental studies on the nanocarbon materials at high reaction temperatures (~600 °C).…”

CrO supported on high-silica HZSM-5 for propane dehydrogenation

“…Propane dehydrogenation (PDH) has drawn particular attention in recent years due to the growing demand of propylene and the increasing production of propane from shale gas [1][2][3][4] . Pt-Sn, CrO x , GaO x , VO x and nanocarbons have been demonstrated to be effective catalysts for PDH [5][6][7][8][9][10][11][12][13][14][15][16][17] . For various reasons, CrO x -Al 2 O 3 based catalysts have been commercially utilized in Catofin process [1 , 4 , 5] .…”