The effect of ionomer content in catalyst layers in anion-exchange membrane water electrolyzers prepared with reinforced membranes (Aemion+™)

Abstract

Anion-exchange membrane water electrolyzers (AEMWEs) have seen a significant rise in performance and durability in recent years. However, systematic studies of membrane-electrode assembly parameters such as ionomer and catalyst contents...

Carbonate Ion Crossover in Zero-Gap, KOH Anolyte CO2 Electrolysis

“…A CCS was also investigated wherein IrO 2 catalyst was cast onto the Ni foam. However, delamination of the anode catalyst layer was observed in Figure S12b,c, similar to that reported in AEMWE studies, where the CCS approach was found to be less robust than CCMs (although delamination of CCMs is also expected over longer periods of operation), despite Figure S12a indicating promising initial performance. , …”

“…While the AEM provides alkalinity to the cathode, the use of a supporting electrolyte at the anode is regarded as necessary for efficient CO 2 and AEM water electrolysis (CO 2 E and AEMWE, respectively) due to enhanced OER kinetics and improved ionic conductivity in the anode catalyst layer. − For CO 2 E, the presence of the supporting electrolyte co-ion (e.g., K + ) is a crucial component in the water management of the system wherein transportation to the cathode by electromigration and water drag from the anode (Figure ) facilitates hydration of the cathode . An additional benefit from the cation species at the cathode is the promotion of CO 2 R by local electrostatic effects. ,, …”

Nickel‐based anodes in anion exchange membrane water electrolysis: a review

“…When optimizing the ionomer content, the optimal amount is generally found to be around 15–20 wt%. This loading generally provides a balance between ohmic, polarization, and mass transport resistances through the catalytic layer, catalyst active site coverage, as well as electrode morphology and durability; this is in line with the optimal amount of ionomer reported in literature for other AEMWE anode catalysts 24,68,81,84,85 . However, in some cases, 51 no effects of ionomer content on anode performance in AEMWE were observed.…”

“…This loading generally provides a balance between ohmic, polarization, and mass transport resistances through the catalytic layer, catalyst active site coverage, as well as electrode morphology and durability; this is in line with the optimal amount of ionomer reported in literature for other AEMWE anode catalysts. 24,68,81,84,85 However, in some cases, 51 no effects of ionomer content on anode performance in AEMWE were observed. These variations in catalyst performance with ionomer content is a clear indication of the importance of ionomer loading optimization for every studied catalyst under its specific set of AEMWE operating conditions.…”

“…Additionally, using an AEM allows for the use of low concentration alkaline electrolytes or distilled water, 7,13 both of which are more favorable to the high alkalinity of the traditional alkaline process. In AEMWE, membranes and ionomers are commonly made with hydrocarbon backbones and cationic groups for hydroxide ion conduction, 7,13,22,24,25 which provides a more economically and environmentally favourable option to the PEMWE perfluorinated membranes, such as Nafion™, which are costly 7,13 and release hydrogen fluoride (HF) upon chemical decomposition. 22,26 One important drawback to the AEMWE process is that it is currently still under Research and Development (R&D), compared to the PEMWE, which is a mature technology for small scale operation.…”