Sustainable production of benzene from lignin.

Meng, Qinglei; Yan, Jiang; Wu, Ruizhi; Liu, Huizhen; Sun, Yang; Wu, NingNing; Xiang, Junfeng; Zheng, Lirong et al. · Nat Commun · 2021

basic_science · Level V

Where this comes from

Abstract

Benzene is a widely used commodity chemical, which is currently produced from fossil resources. Lignin, a waste from lignocellulosic biomass industry, is the most abundant renewable source of benzene ring in nature. Efficient production of benzene from lignin, which requires total transformation of C<sub>sp2</sub>-C<sub>sp3</sub>/C<sub>sp2</sub>-O into C-H bonds without side hydrogenation, is of great importance, but has not been realized. Here, we report that high-silica HY zeolite supported RuW alloy catalyst enables in situ refining of lignin, exclusively to benzene via coupling Bronsted acid catalyzed transformation of the C<sub>sp2</sub>-C<sub>sp3</sub> bonds on the local structure of lignin molecule and RuW catalyzed hydrogenolysis of the C<sub>sp2</sub>-O bonds using the locally abstracted hydrogen from lignin molecule, affording a benzene yield of 18.8% on lignin weight basis in water system. The reaction mechanism is elucidated in detail by combination of control experiments and density functional theory calculations. The high-performance protocol can be readily scaled up to produce 8.5 g of benzene product from 50.0 g lignin without any saturation byproducts. This work opens the way to produce benzene using lignin as the feedstock efficiently.

Medical subject headings