Highly conductive partially cross-linked poly(2, 6-dimethyl-1, 4-phenylene oxide) as anion exchange membrane and ionomer for water electrolysis. (29th October 2021)

• Record Type: Journal Article
• Authors: Feng, Zhiming; Esteban, Pilar Ocón; Gupta, Gaurav; Fulton, David A.; Mamlouk, Mohamed
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 75(2021)
• Page Start: 37137
• Page End: 37151
• Publication Date: 2021-10-29
• Subjects: PPO -- Poly(2, 6-dimethyl-1, 4-phenylene oxide) -- AEM -- Friedel-crafts reactions -- Water electrolyser; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.09.014
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Cross-linked quaternised Poly(2, 6-dimethyl-1, 4-Phenylene Oxide) (QPPO)-based membranes were prepared via Friedel-Crafts reactions using SnCl4 catalyst, 1, 3, 5-trioxane and chlorotrimethylsilane as environmentally-friendly chloromethylating reagents. New equations to calculate the degree of chloromethylation ( DC ) and cross-linking degree ( CLD ) were proposed. Ionic conductivity of 133 mS cm −1 at 80 °C was obtained, one of the highest reported for QPPO based membranes. We have compared QPPO to chloromethylated polystyrene- b -poly(ethylene/butylene)-b-polystyrene (SEBS) ionomer and report on the importance of ionomer-membrane interaction as well as the trade-off between swelling ratio and conductivity on performance and mechanical stability of AEM water electrolyser. Exsitu stability testing after 500 h in 1 M KOH showed membranes retained up to 94% of their original IEC . QPPO was employed as both membranes and ionomers in electrolyser tests. QPPO membranes exhibited area specific resistance of 104 mΩ cm −2 and electrolyser current density of 814 mA cm −2 at 2.0 V in 0.1 M NaOH solution at 40 °C. Graphical abstract: Image 1 Highlights: New equations to calculate the degree of chloromethylation (DC) and cross-linking degree (CLD). Synthesis and fabrication of self-crosslinking PPO based AEM with ionic conductivity >0.13 S cm −1 . Electrolyser current density of 814 mA cm −2 at 2.0 V at 40 °C. Area specific resistance of 104 mΩ cm −2 in 0.1 M NaOH solution at 40 °C.