An Investigation of a (Vinylbenzyl) Trimethylammonium and N-Vinylimidazole-Substituted Poly (Vinylidene Fluoride-Co-Hexafluoropropylene) Copolymer as an Anion-Exchange Membrane in a Lignin-Oxidising Electrolyser

Abstract

Electrolysis is seen as a promising route for the production of hydrogen from water, as part of a move to a wider “hydrogen economy”. The electro-oxidation of renewable feedstocks offers an alternative anode couple to the (high-overpotential) electrochemical oxygen evolution reaction for developing low-voltage electrolysers. Meanwhile, the exploration of new membrane materials is also important in order to try and reduce the capital costs of electrolysers. In this work, we synthesise and characterise a previously unreported anion-exchange membrane consisting of a fluorinated polymer backbone grafted with imidazole and trimethylammonium units as the ion-conducting moieties. We then investigate the use of this membrane in a lignin-oxidising electrolyser. The new membrane performs comparably to a commercially-available anion-exchange membrane (Fumapem) for this purpose over short timescales (delivering current densities of 4.4 mA cm−2 for lignin oxidation at a cell potential of 1.2 V at 70 °C during linear sweep voltammetry), but membrane durability was found to be a significant issue over extended testing durations. This work therefore suggests that membranes of the sort described herein might be usefully employed for lignin electrolysis applications if their robustness can be improved.

Amphoteric Membrane Loaded with a Noble Metal-Free Hollow Spherical NiCoP@rGO Bifunctional Electrocatalyst for Alkaline Water Electrolyzers

“…The finite supply of fossil fuels and environmental pollution are major concerns for global climate and have accelerated the implementation of alternative energy technologies without any emission of greenhouse gases. 1 Effective utilization of renewable energy (solar, wind, etc.) has great potential in this regard.…”

Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments

“…6). The most common relevant backbones cited in the literature used for AEMs are: polysulphone type [262][263][264][265][266] poly(ether ketone) type, [267][268][269][270] poly(ether imide) type, [271][272][273] poly(ether oxadiazole) type, [275][276][277] and poly(phenylene oxide) type, 274,[278][279][280][281][282] polyphenylene type, [283][284][285] fluorinated type, [286][287][288][289][290][291] polybenzimidazole type, [292][293][294][295][296][297][298] polyethylene type, [299][300][301][302][303][304][305][306] and polystyrene type. 264,…”

Recent progress in anion exchange membranes (AEMs) in water electrolysis: synthesis, physio-chemical analysis, properties, and applications

“…Recently, various ratios (4-10%) of (vinylbenzyl)trimethylammonium chloride were functionalized with the uorinated polymer (PVIB), revealing the increase in the IEC (1.43-1.82 mmol g −1 ). 326 Increasing the number of (vinylbenzyl)trimethylammonium chloride in the membrane could enhance the ion exchanges between the polymer backbone and QAs. Another research found that the IECs decreased from 2.84 to 1.55 mmol g −1 when the amount of extended alkyl chain-based bis-piperidinium cation groups in the quaternized membrane (e.g., QPBPip-Ac) was increased (from 33% to 67%).…”