Jump to main content
Jump to site search

Issue 20, 2019
Previous Article Next Article

Cleavage of lignin C–O bonds over a heterogeneous rhenium catalyst through hydrogen transfer reactions

Author affiliations

Abstract

Hydrogenolysis is one of the most popular strategies applied in the depolymerization of lignin for the production of aromatic chemicals. Currently, this strategy is mainly conducted under high hydrogen pressure, which can pose safety risks and is not sustainable and economical. Herein, we reported that heterogeneous rhenium oxide supported on active carbon (ReOx/AC) exhibited excellent activity in the selective cleavage of lignin C–O bonds in isopropanol. High yields of monophenols (up to 99.0%) from various lignin model compounds and aromatic liquid oils (>50%) from lignin feedstock were obtained under mild conditions in the absence of H2. The characterization of the catalyst by X-ray absorption fine structure, X-ray photoelectron spectroscopy and H2-temperature-programed reduction suggested that the activity of ReOx/AC could be attributed to the presence of ReIV–VI. The interaction between the surface oxygen groups of the active carbon and rhenium oxide could also play an important role in the cleavage of the C–O bonds. Notably, an ReOx/AC-catalyzed C–O bond cleavage pathway beyond a typical deoxydehydration mechanism was disclosed. More importantly, 2D-HSQC-NMR and GPC characterizations showed that ReOx/AC exhibited high activity not only in β-O-4 cleavage, but also in the deconstruction of more resistant β-5 and β–β linkages in lignin without destroying the aromatic ring. This study paves the way for the development of rhenium-based catalysts for the controlled reductive valorization of realistic lignin materials through a hydrogen transfer pathway.

Graphical abstract: Cleavage of lignin C–O bonds over a heterogeneous rhenium catalyst through hydrogen transfer reactions

Back to tab navigation

Supplementary files

Publication details

The article was received on 22 May 2019, accepted on 16 Aug 2019 and first published on 19 Aug 2019


Article type: Paper
DOI: 10.1039/C9GC01710K
Green Chem., 2019,21, 5556-5564

  •   Request permissions

    Cleavage of lignin C–O bonds over a heterogeneous rhenium catalyst through hydrogen transfer reactions

    B. Zhang, Z. Qi, X. Li, J. Ji, L. Zhang, H. Wang, X. Liu and C. Li, Green Chem., 2019, 21, 5556
    DOI: 10.1039/C9GC01710K

Search articles by author

Spotlight

Advertisements