Changzhi Li

Selective demethoxylation of lignin-derived guaiacols requires sufficient interfacial hydrogen for CAr–OCH3 bond cleavage, whereas excess hydrogen promotes aromatic-ring hydrogenation and deep deoxygenation. Controlled sulfurization of Cu-promoted molybdenum oxide created nanoscale oxide–sulfide interfaces that balance target-bond activation with hydrogen delivery. Optimization of Cu/Mo ratio and sulfur content afforded Cu0.5-Mo-S0.1, which achieved 95.4% conversion and 97.9% alkylphenol selectivity at 250 °C and 3 MPa H2 while retaining activity over seven cycles. X-ray diffraction (XRD), Raman, and high-resolution transmission electron microscopy (HRTEM) support intimate contact between nanoscale MoO2 and MoS2 domains, while sulfur-induced shifts of Mo X-ray photoelectron spectroscopy (XPS) components to lower binding energies suggest a plausible Mo–O–Mo–S interfacial motif. Bader analysis revealed interfacial charge redistribution consistent with XPS, supporting its electronic plausibility. In situ Fourier transform infrared (FT-IR) spectroscopy, hydrogen-spillover experiment, and density functional theory (DFT) calculation elucidate the interface-mediated reaction mechanism. The Mo–O–Mo–S boundary promotes the vertical adsorption of lignin-derived oxygenates toward the interface, facilitating direct CAr–OCH3 bond cleavage and subsequent hydrogenation of the intermediates, while weakening alkylphenol adsorption to promote product desorption. Meanwhile, Cu–S bonding attenuates hydrogen spillover, thereby suppressing aromatic-ring hydrogenation. Alkylphenol selectivity exceeded 98% across the examined para-alkyl guaiacols. Thus, matching selective C–O activation with moderated interfacial hydrogen supply provides a strategy for selective demethoxylation.

Lignin represents a promising alternative to fossil fuels for producing high‐value aromatic chemicals and carbon‐based materials. The integrated valorization of lignin for the production of carbon materials and chemicals is a crucial sustainable strategy. In this work, lignin‐derived carbon‐supported tungsten catalysts (W@CL) were fabricated via a facile chelation‐anchoring strategy coupled with one‐step in situ carbonization for lignin hydrogenolysis. This strategy achieved the uniform dispersion of tungsten trioxide (WO ₃ ) and the controllable reduction of tungsten during carbonization, thereby generating abundant catalytically active sites. After optimizing the preparation procedure and conditions, W@CL‐800 obtained at 800 °C exhibited optimal selective hydrogenolysis performance with high yields of phenol (84.2%) and ethylbenzene (83.6%). For real lignin, W@CL‐800 afforded 64.3 wt% aromatic oily products, mainly composed of monophenol and their 4‐alkyl derivatives. Active site analysis and cyclic stability tests revealed the synergistic effects of WO ₃ and metallic tungsten (W ⁰ ) toward the selective hydrogenolysis of lignin, and highlighted the advantages of this chelation‐anchored strategy. Mechanistically, methanol and hydrogen played coupled functions in bond cleavage and intermediate hydrogenolysis. This work provides a simple and sustainable strategy for lignin upgrading and high‐value utilization.

Sustainably sourced lignin presents great potential as carbon‐based metal catalyst supports owing to its high carbon content as well as the ability to coordinate with metal ions. However, the rational regulation of the lignin‐supported metal catalyst fabrication process to optimize their morphology and activity remains a challenge. Herein, we proposed a straightforward strategy to regulate the N content and species in the supports, thereby governing the nucleation behavior of Ru nanoparticles by varying the sintering temperature, for targeted enhancement of the catalytic performance of lignin‐supported Ru‐based catalysts. The sintering temperature of 700 °C was conducive to reducing the escape of elemental N and maintaining a high percentage of pyridinic‐N species, which was beneficial to the adsorption and immobilization of Ru by the supports, resulting in the formation of Ru nanoparticles with a small size (1.93 nm). In the catalytic transfer hydrogenation (CTH) of levulinic acid (LA) to γ‐valerolactone (GVL) using isopropanol as the hydrogen donor, the obtained catalyst demonstrated nearly 100% LA conversion and GVL selectivity under mild conditions (120 °C) with good reusability. This strategy achieves directional control over the structure of lignin‐supported metal catalysts through a simple method, providing guidance for the efficient synthesis of these catalysts.

The massive CO ₂ emission arising from fossil fuel combustion has exacerbated climate crises and disrupted ecological balance, driving the need for sustainable processes for the efficient utilization of renewable resources. Lignocellulose represents as a promising alternative to fossil‐based feedstock, while the inherent structural recalcitrance significantly hinders its efficient conversion. Mechanical ball milling is considered as a potential strategy for lignocellulose valorization for its intensive mechanical energy to disrupt the physical architecture of lignocellulose. Currently, the existing reviews mostly focus on the application of mechanical ball milling for biomass‐based materials preparation, lacking integrated discussions on the application for lignocellulose separation and depolymerization. This review emphasized the synergistic effect of the mechanochemical strategy for structural disruption and chemical activation, which includes the effective separation of lignin and cellulose and their depolymerization to obtain value‐added monomers and platform chemicals. Furthermore, the potential and energy advantages of mechanical ball milling for industrial‐scale applications were elaborated by comparing different mechanochemical strategies, combined with energy consumption comparison and process scaling. Finally, future perspectives on the precise optimization of mechanical ball‐milling systems are proposed. This review offers promising guidance on the valorization of lignocellulosic biomass.

Catalytic arene hydrogenation offers a direct pathway to saturated carbocycles. It can also be exploited to upgrade lignin‐derived aromatics. We have found that one of the most easily available rhodium compounds, rhodium(III) oxide, (Rh ₂ O ₃ ), is a highly efficient heterogeneous catalyst for arene hydrogenation in aqueous conditions. A diverse array of arene substrates, including those derived from lignin, underwent smooth conversion into their corresponding saturated products under 5 bar of hydrogen in water. This hydrogenation protocol displayed good compatibility with functional groups and showed tuneable chemoselectivity for α , β ‐unsaturated aryl ketones. Given the easy commercial availability of Rh ₂ O ₃ , the method provides a convenient route for synthesising three‐dimensional alicyclic compounds from two‐dimensional aromatic precursors, including those readily accessible from lignin depolymerisation.

A Mn-loaded lignin-derived carbon was prepared for water electrolysis via an in situ anchoring and one-step carbonization strategy. The N-doping played a crucial synergistic role in enhancing the OER and HER performance.