Hydrogen‐Transfer Reductive Catalytic Fractionation of Lignocellulose: High Monomeric Yield with Switchable Selectivity

Abstract

Lignin solubilization and in situ hydrogenolysis are crucial for reductive catalytic fractionation (RCF) of lignocellulose to aromatic monomers. In this study, we reported a typical hydrogen bond acceptor of choline chloride (ChCl) to tailor the hydrogen‐donating environment of the Ru/C‐catalyzed hydrogen‐transfer RCF of lignocellulose. The ChCl‐tailored hydrogen‐transfer RCF of lignocellulose was conducted under mild temperature and low‐pressure (<1 bar) conditions, which was applicable to other lignocellulosic biomass sources. We obtained an approximate theoretical yield of propylphenol monomer of 59.2 wt % and selectivity of 97.3 % using an optimal content of ChCl (10 wt %) in ethylene glycol at 190 °C for 8 h. When the content of ChCl in ethylene glycol was increased to 110 wt %, the selectivity of propylphenol switched toward propylenephenol (yield of 36.2 wt % and selectivity of 87.6 %). The findings in this work provide valuable information for transforming lignin from lignocellulose into value‐added products.

Solvent-triggered directional lignin valorization towards monomeric acetals or lignin polyols

“…This stabilized lignin holds promise for applications in the polymer industry, offering opportunities for its versatile and expanded utilization. 41–43 In summary, the design and implementation of the biphasic DES system offer great potential for achieving diversified and maximum utilization of lignin. By manipulating reaction pathways and producing functionalized lignin, this approach opens up new avenues for the valorization of lignin and paves the way for its enhanced application in various industries.…”

Hydrogen‐transfer strategy in lignin refinery: Towards sustainable and versatile value‐added biochemicals

“…Reproduced under the CC BY-NC-ND license. [204] Copyright 2023, The Authors. Published by Wiley-VCH.…”

“…Li et al developed a tailored hydrogen-transfer RCF method to birch lignocellulose. [204] The process utilizes a modified solvent system comprising EG and choline chloride. This customized solvent mixture establishes a "partial deep eutectic solvent environment" that substantially improves the solubility of lignin, thereby expediting the generation of valuable monomeric products.…”

“…d) The birch monomer yield of the hydrogen-transfer RCF assisted with different content of hydrogen bond acceptor. Reproduced under the CC BY-NC-ND license [204]. Copyright 2023, The Authors.…”

Harnessing Atomically Dispersed Cobalt for the Reductive Catalytic Fractionation of Lignocellulose

“…[ 14 ] This approach is generally carried out in the presence of a transition metal catalyst under a reduced atmosphere, being termed as reductive catalytic fractionation (RCF). [ 15–17 ] The transition metal catalysts, which dominate the cleavage of lignin linkages and subsequent stabilization steps, have been evolved rapidly in the last decade. In early period, commercial catalysts with high‐loaded ( ca .…”