Structures and properties of polymers in ion exchange membranes for hydrogen generation by water electrolysis

Abstract

Water electrolysis (WE) is an electrochemical process that splits water and forms hydrogen and oxygen, in presence of catalyst. This is a rapidly developing technology owing to its extreme importance in the generation of hydrogen. Membrane-based WE involves the use of anion exchange, proton exchange and bipolar membranes, among which the anion exchange membrane-based WE technology is in the most advanced stage, followed by the proton exchange membrane-based WE. While, the bipolar membrane-based WE is the most nascent technology. Among the different categories of membranes used, polymer-based membranes are the most acceptable ones. It is evident that the structure and properties of the polymers that constitute a membrane play the most important role in determining its applicability in WE application. Keeping this in mind, this review is dedicatedly focused on the different polymers that have been majorly used so far in fabrication of anion exchange, proton exchange, and bipolar membranes for WE, and exclusively analyzes the influence imparted by the structure and properties of the involved polymers on the final performance of the membranes.

Development of highly alkaline stable anion conductive polymers with fluorene backbone for water electrolysis

“…In addition, PF is easily obtained as the sufficiently high‐molecular weight with narrow polydispersity by the Suzuki‐Miyaura coupling polymerization. As the Suzuki‐Miyaura cross‐coupling of organodiboronic acid and organodihalides gives alternating copolymers, the IEC of the AEM can be selected by changing the combination of monomers 35 . The alkyl spacer between the polymer main chain and ion exchange groups is another crucial molecular design point.…”

“…Therefore, aromatic polymers with no heteroatom bonds in the polymer main chain are expected to show high chemical stability. For the study of polymer electrolyte fuel cells using AEMs, polyphenylene‐type and polyfluorene‐type AEMs have been reported as the desired main chains with high‐chemical stabilities 21,33–37 . Bae et al reported that AEMs with a terphenyl backbone with high‐alkaline stability maintain ion exchange capacity (IEC) even after immersion in an basic aqueous solution (1 M NaOH) at 95°C for 60 days 38 .…”

Anion exchange membrane water electrolysis for sustainable large‐scale hydrogen production

“…[1,2] Hydrogen, as a promising energy carrier, plays a significant role in the carbon-neutrality world because of its various advantages: sustainability, nontoxicity, and high energy contents. [3,4] The use of hydrogen mitigates the environmental impacts that occur with carbon-based fuels. However, unlike fossil fuels, hydrogen as a form of fuel is not available to use in nature.…”

What is Next in Anion‐Exchange Membrane Water Electrolyzers? Bottlenecks, Benefits, and Future

“…[10][11][12][13][14][15][16][17] The recent development of AEM and anion-exchange ionomers for AEM-WE or AEM fuel cell application was reviewed in Refs. [18][19][20][21][22]. Particularly, AEMs developed for AEM-WE application were summarized in Refs.…”

“…[20] In Ref. [21], a comprehensive Review related to the structures and properties of polymers in anion and cation exchange membranes for water electrolysis application is presented. Advances in AEMs for fuel cells and electrolyzers application were also presented by Mandal.…”