Influence of Headgroups in Ethylene-Tetrafluoroethylene-Based Radiation-Grafted Anion Exchange Membranes for CO Electrolysis.

The performance of zero-gap CO electrolysis (COE) is significantly influenced by the membrane's chemical structure and physical properties due to its effects on the local reaction environment and water/ion transport. Radiation-grafted anion-exchange membranes (RG-AEM) have demonstrated high ionic conductivity and durability, making them a promising alternative for COE. These membranes were fabricated using two different thicknesses of ethylene-tetrafluoroethylene polymer substrates (25 and 50 μm) and three different headgroup chemistries: benzyl-trimethylammonium, benzyl--methylpyrrolidinium, and benzyl--methylpiperidinium (MPIP).

Enriching Surface-Accessible CO in the Zero-Gap Anion-Exchange-Membrane-Based CO Electrolyzer.

Zero-gap anion exchange membrane (AEM)-based CO electrolysis is a promising technology for CO production, however, their performance at elevated current densities still suffers from the low local CO concentration due to heavy CO neutralization. Herein, via modulating the CO feed mode and quantitative analyzing CO utilization with the aid of mass transport modeling, we develop a descriptor denoted as the surface-accessible CO concentration ([CO ] ), which enables us to indicate the transient state of the local [CO ]/[OH ] ratio and helps define the limits of CO -to-CO conversion. To enrich the [CO ] , we developed three general strategies: (1) increasing catalyst layer thickness, (2) elevating CO pressure, and (3) applying a pulsed electrochemical (PE) method.