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

Lignin, the most prevalent natural source of polyphenols on Earth, offers substantial possibilities for the conversion into aromatic compounds, which is critical for attaining sustainability and carbon neutrality. The hydrogen-transfer method has garnered significant interest owing to its environmental compatibility and economic viability. The efficacy of this approach is contingent upon the careful selection of catalytic and hydrogen-donating systems that decisively affect the yield and selectivity of the monomeric products resulting from lignin degradation.

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

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.

Deep eutectic solvents boosting solubilization and Se-functionalization of heteropolysaccharide: Multiple hydrogen bonds modulation.

In this study, the favorable feasibility of deep eutectic solvents (DESs) in solubilization and functionalization of natural heteropolysaccharide was validated by experiments and density functional theory calculations. This revealed that choline chloride-based DES/DMSO (dimethyl sulfoxide) binary mixed solvents possessed more and stronger hydrogen bonding sites, facilitating the balance between disruption and reconstruction of hydrogen bonds within branched heteropolysaccharide from Artemisia sphaerocephala (PAS) and achieving efficient solubilization. Further, due to the full exposure and activation of polysaccharide hydroxyls, the efficiency of DES/DMSO-mediated novel Se-functionalization was substantially enhanced compared to the conventional selenylation methods.

Acid site-regulated solid acids for polysaccharide Se-functionalization: Structural explanations for high reactivity.

In this work, the application of acid site-regulated solid acids in Se-functionalization of polysaccharide is evaluated for the first time, which aimed to further improve reaction efficiency and realize environmentally friendly chemistry. A series prepared MO/HZSM-5 catalysts possesses standard crystal structure, large specific surface area, pore volume, aperture as well as strong acidity. An efficient substitution of seleno-group on polysaccharide backbone is promoted by regulating the acid site of solid acids (Se content up to 15,170.