Electrochemical depolymerization of lignin into renewable aromatic compounds in a non-diaphragm electrolytic cell

Abstract

Electrochemical depolymerization of lignin for production of renewable aromatic compounds is presented.In the designed non-diaphragm electrolytic cell, lignin in alkaline electrolyte was directly electro-oxidized on the anode and chemically oxidized by the electro-generated H 2 O 2 formed on the cathode simultaneously. The linkages among C9 units in lignin were broken down and more than 20 kinds of low-molecular-weight (LMW) aromatic compounds containing hydroxyl, aldehyde, carbonyl and carboxyl groups were generated and identified by GC-MS and ESI-MS/MS measurements. The effects of electrolysis conditions on the concentration of H 2 O 2 , the decomposition rate of H 2 O 2 into reactive oxygen species (ROS) and the yields of LMW products were investigated in detail. Results show that H 2 O 2 and ROS play very important roles in lignin depolymerization. The electrolysis conditions for producing higher concentrations of H 2 O 2 and ROS are in favor of giving higher yields of LMW products.59.2% of lignin was depolymerized into LMW products after 1 hour-electrolysis at 80 C under a current density of 8 mA cm À2 with extra O 2 supplement.

Novel Mixed‐Mode Stationary Phases for Chromatographic Separation of Complex Mixtures of Decomposed Lignin

“…Electrochemical lignin degradation was established as a potential sustainable alternative to common degradation processes. The major benefit of electrochemical degradation is the availability of single electron transfer reactions that induce oxidative and reductive bond cleavages of the lignin polymer . Electrochemical decomposition yields both simple low molecular weight products as previously observed as well as complex distributions of combinatorial products .…”

“…The major benefit of electrochemical degradation is the availability of single electron transfer reactions that induce oxidative and reductive bond cleavages of the lignin polymer . Electrochemical decomposition yields both simple low molecular weight products as previously observed as well as complex distributions of combinatorial products . The latter mixtures have been classified using enhanced mass defect filtering techniques and high resolution mass spectrometry (HRMS), revealing significant hidden complexity from isobaric components.…”

Improvement of lignin yield and purity from corncob in the presence of steam explosion and liquid hot pressured alcohol

“…The HSQC spectrum of LRF was done by a Bruker AV 600 spectrometer. 100 mg acetylated lignin was dissolved in 0.5 mL DMSO-d 6 …”

Development of a Three-Dimensional Structured Carbon Fiber Felt/β-PbO2 Electrode and Its Application in Chemical Oxygen Demand Determination

“…The amount of ·OH generated in electro-catalytic system is associated with the activity of anode. Since bromocresol green (BG) can only be destroyed by • OH radicals, the decrement of BG in a certain time is an indicator for the generation rate of • OH radicals [35][36][37]. As shown by the histogram in Fig.…”