Closed-Loop Lignin Valorization: Integrated Chelation-Carbonization Fabrication of Carbon-Supported Tungsten Catalysts for Catalytic Hydrogenolysis of Lignin.

Abstract

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 (WO3) 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 WO3 and metallic tungsten (W0) 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.