The aim of this study is to quantify the hydrogen production rate in an anion exchange membrane (AEM) lignin electrolysis cell. Two non-precious and nanostructured metal and metal oxide electrocatalysts were developed and used as the anodic catalysts in a lignin electrolysis process. H 2 production rates, energy consumption rates and faradaic efficiency were measured using β-PbO 2 /MWNTs and Ni-Co/TiO 2 electrocatalysts as the anode, where electrochemical depolymerization of lignin occurs. Our results were then compared with recent efforts for lignin electrolysis in the literature. This work demonstrates that the β-PbO 2 /MWNTs nanocomposite is the more stable and active electrocatalyst in this process. At the end, our results showed that using β-PbO 2 /MWNTs as the anodic electrocatalyst can enhance lignin oxidation rates, with a corresponding increase in the rate of H 2 production at the cathode. As a result, this can lead to high hydrogen evolution rates (∼45.6 mL/h), and increase energy efficiency by 20%, compared to a commercial alkaline water electrolyzer.

No abstract

Lignin has been submitted to electrochemical oxidation in the presence of nickel (Ni), cobalt (Co) and Ni-Co bimetallic electrocatalysts, which were prepared by a simple electrochemical deposition process. The composition and morphology of the catalyst were studied by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA). The effects of the three electrocatalysts on the electrochemical oxidation of lignin were observed by cyclic voltammetry and chronoamperometry. The degradation products were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). The rate of electrochemical oxidation of lignin is higher with Ni-Co bimetallic electrocatalyst with higher Co contents and the main products obtained were vanillin, apocynin and 3-methylbenzaldehyde.

In this paper, we report on our efforts to evaluate NiSn as anode electrocatalysts for simultaneous hydrogen evolution and lignin depolymerization in a biomass-depolarized electrolyzer. Different ratios of NiSn alloys were synthesized through co-electrodeposition of Ni and Sn from a pyrophosphate plating bath. The composition and morphology of the electrocatalysts were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), and X-ray powder diffraction (XRD) techniques. Electrochemical measurements were carried out in a typical three electrode-cell system to evaluate electrocatalyst kinetics in 1.0 M NaOH solution. We evaluated the alloys as anode electrocatalysts in a flow-through biomass-depolarized electrolyzer. Gas chromatography-mass spectroscopy (GC-MS) was employed to evaluate the production rates of vanillin as one of the main oxidation products. It was found that using NiSn20% electrode as the anode results in higher electrochemical reaction rates and potentially higher rate of aromatic products.

No abstract