Synthesis of Vanillin and Guaiacol through [Hmim]Tf2N Ionic Liquid Catalyzed Lignin-Directed Pyrolysis at Low Temperature and Voltage

Graphical Electrochemically catalyzed ionic liquid technology facilitates lignin cleavage at 230 °C, with vanillin yields reaching 88.54 % at 3 V and guaiacol yields at 48.24 % at 4 V, showcasing enhanced productivity in lignin-derived compounds. Significant attention has been devoted to using biomass as a renewable resource to address the energy crisis and mitigate environmental pollution. Biomass, a potential substitute for fossil fuels, contains a substantial amount of lignin, ranging from 10 % to 25 %. Hence, it is crucial to research lignin depolymerization. In this study, the use of electrochemically catalyzed ionic liquids enabled the cracking of lignin at low temperatures. Specifically, by applying a low voltage at 230 °C, the controlled generation of vanillin and guaiacol was achieved. The concentration of vanillin in the depolymerized lignin reached 88.54 % under 3 V conditions. Similarly, it is presumed that the yield of guaiacol at 4 V is 48.24 %. These findings have significant implications for the targeted management of lignin depolymerization byproducts. Ultimately, this project establishes a framework for the high-value utilization of biomass and provides new perspectives on addressing the energy problem and environmental degradation.