A Review on Membranes and Catalysts for Anion Exchange Membrane Water Electrolysis Single Cells

Abstract

The research efforts directed at advancing water electrolysis technology continue to intensify together with the increasing interest in hydrogen as an alternative source of energy to fossil fuels. Among the various water electrolysis systems reported to date, systems employing a solid polymer electrolyte membrane are known to display both improved safety and efficiency as a result of enhanced separation of products: hydrogen and oxygen. Conducting water electrolysis in an alkaline medium lowers the system cost by allowing non-platinum group metals to be used as catalysts for the complex multi-electron transfer reactions involved in water electrolysis, namely the hydrogen and oxygen evolution reactions (HER and OER, respectively). We briefly review the anion exchange membranes (AEMs) and electrocatalysts developed and applied thus far in alkaline AEM water electrolysis (AEMWE) devices. Testing the developed components in AEMWE cells is a key step in maximizing the device performance since cell performance depends strongly on the structure of the electrodes containing the HER and OER catalysts and the polymer membrane under specific cell operating conditions. In this review, we discuss the properties of reported AEMs that have been used to fabricate membrane-electrode assemblies for AEMWE cells, including membranes based on polysulfone, poly(2,6-dimethyl-p-phylene) oxide, polybenzimidazole, and inorganic composite materials. The activities and stabilities of tertiary metal oxides, metal carbon composites, and ultra-low Pt-loading electrodes toward OER and HER in AEMWE cells are also described.

Overview: State-of-the Art Commercial Membranes for Anion Exchange Membrane Water Electrolysis

“…A potential solution to this is anion exchange membrane (AEM) water electrolysis (AEMWE) [11][12][13]. AEMWE is a combination of alkaline water electrolysis and PEMWE: The electrode chambers are separated by a thin, dense, non-porous polymer membrane, as in PEMWE.…”

Effect of Unbleached Rice Straw Cellulose Nanofibers on the Properties of Polysulfone Membranes

“…Polysulfone (PSF) is one of the attractive polymers due to its good mechanical properties, thermal stability, chemical resistance, transparency, and flexibility [1]. PSF is used in different kinds of membranes such as anion-exchange membranes [2]; hemodialyzer membranes [3]; gas separation membranes [4]; pressure-driven membranes, i.e., ultra- and nanofiltration membranes [5]; osmotically-driven membranes for desalination and ions removal [6]; proton-exchange membranes fuel cells [7]; membranes for use in artificial organs [8]; and membranes used in dehydration of solvents by pervaporation [9].…”

Highly cost-effective platinum-free anion exchange membrane electrolysis for large scale energy storage and hydrogen production

“…Recently, PBI-based anion exchange membranes received much attention, which were used as AEM for AEM electrolysis. 28 The PBI based anion exchange membrane shows high thermal (T g ¼ 425-436 C), mechanical and chemical stability. Also, it exhibits rendered anion conducting when doping with KOH.…”