Chapter 6. Alkaline Anionic Exchange Membrane Water Electrolysers

Mamlouk, Mohamed; Manolova, Mila

doi:10.1039/9781788016049-00180

Cited by 3 publications

(17 citation statements)

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“…The price for H 2 production by WE coupled with wind energy could be below 3.8 €/kg H2 if the WE is used at an 80% annual capacity, has a CAPEX value of 800 €/kW, and has a cell efficiency of 80% at OPEX costs corresponding to renewable electricity costs of 70 €/MWh . Proost and others suggest that WEs could become more competitive to SMR as CAPEX prices of WEs are predicted to decrease with an increase in manufacturing (taking advantage of the economy of scale) and to a lesser extent also continue to decrease through additional research and development contributions. ,, This seems reasonable considering that the CAPEX prices of PEMWEs decreased by 1 order of magnitude between 2000 and 2010 and continue to steadily decrease, as demonstrated in Table . − These trends suggest that H 2 production by WEs will become competitive if low-cost electricity is used. , …”

Section: To and From H2 Produced Via Water Electrolysis: Sources Cost...mentioning

confidence: 99%

“…As seen from Figure , a higher temperature ( T ) lowers E cell , which is beneficial for the electrochemical reactions, increases the counterion transport, and facilitates H 2 and O 2 separation as the gas solubility decreases with increasing T . − A higher pressure ( P ) increases E cell according to the Nernst equation, although the increase is not pronounced. In fact, the availability of compressed H 2 directly from a WE is a benefit, reducing the cost of mechanical H 2 compression provided that the compression remains in the 30–50 bar range. ,, WE operation at higher pressures can require the reinforcement of thinner membranes (e.g., in the case of PEMWEs < 125 μm) to increase their mechanical strength and achieve higher WE efficiencies.…”

Section: To and From H2 Produced Via Water Electrolysis: Sources Cost...mentioning

confidence: 99%

“…Introducing resonance-stabilized structures in or near cationic groups opens another potential antidegradation pathway. The positive charges are delocated over more than one N (or P) atom by using aromatic diamine or multiple N or P systems, leading to resonance stabilization, as seen for, e.g., the heterocyclic imidazolium system . Another example of a resonance-stabilized AEM structure is n -alkylaminophosphonium in poly(ethylene) backbones .…”

Section: Anion-exchange Membranesmentioning

confidence: 99%

“…References are made where needed to scientific knowledge established for well-studied PEMWEs and fuel cells (FCs). This Review differs from recent publications − as it presents a comprehensive analysis of all components of an AEMWE up to the single-cell level and reviews AEMWE single-cell performances for cells that have shown at least 100 h of operation. Performance results and needs of materials development and engineering are given based on high-level analyses.…”

Section: Introductionmentioning

confidence: 99%

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Anion-Exchange Membrane Water Electrolyzers

et al. 2022

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This Review provides an overview of the emerging concepts of catalysts, membranes, and membrane electrode assemblies (MEAs) for water electrolyzers with anion-exchange membranes (AEMs), also known as zero-gap alkaline water electrolyzers. Much of the recent progress is due to improvements in materials chemistry, MEA designs, and optimized operation conditions. Research on anion-exchange polymers (AEPs) has focused on the cationic head/backbone/side-chain structures and key properties such as ionic conductivity and alkaline stability. Several approaches, such as cross-linking, microphase, and organic/inorganic composites, have been proposed to improve the anion-exchange performance and the chemical and mechanical stability of AEMs. Numerous AEMs now exceed values of 0.1 S/cm (at 60–80 °C), although the stability specifically at temperatures exceeding 60 °C needs further enhancement. The oxygen evolution reaction (OER) is still a limiting factor. An analysis of thin-layer OER data suggests that NiFe-type catalysts have the highest activity. There is debate on the active-site mechanism of the NiFe catalysts, and their long-term stability needs to be understood. Addition of Co to NiFe increases the conductivity of these catalysts. The same analysis for the hydrogen evolution reaction (HER) shows carbon-supported Pt to be dominating, although PtNi alloys and clusters of Ni(OH)2 on Pt show competitive activities. Recent advances in forming and embedding well-dispersed Ru nanoparticles on functionalized high-surface-area carbon supports show promising HER activities. However, the stability of these catalysts under actual AEMWE operating conditions needs to be proven. The field is advancing rapidly but could benefit through the adaptation of new in situ techniques, standardized evaluation protocols for AEMWE conditions, and innovative catalyst-structure designs. Nevertheless, single AEM water electrolyzer cells have been operated for several thousand hours at temperatures and current densities as high as 60 °C and 1 A/cm2, respectively.

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Section: To and From H2 Produced Via Water Electrolysis: Sources Cost...mentioning

confidence: 99%

Section: To and From H2 Produced Via Water Electrolysis: Sources Cost...mentioning

confidence: 99%

Section: Anion-exchange Membranesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Anion-Exchange Membrane Water Electrolyzers

et al. 2022

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“…The NiFeO x is instead characterized by a proper content of NiO compared to NiFe 2 O x and Fe 2 O 3 phases. NiO is a good catalyst for oxygen evolution in alkaline systems [55]. Its synergy with the spinel phase appears relevant to promote the OER process under practical conditions.…”

Section: Electrochemical Experimentsmentioning

confidence: 99%

Investigation of NiFe-Based Catalysts for Oxygen Evolution in Anion-Exchange Membrane Electrolysis

et al. 2020

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NiFe electrodes are developed for the oxygen evolution reaction (OER) in an alkaline electrolyser based on an anion exchange membrane (AEM) separator and fed with diluted KOH solution as supporting electrolyte. This study reports on the electrochemical behaviour of two different NiFe-oxide compositions (i.e., Ni1Fe1-oxide and Ni1Fe2-oxide) prepared by the oxalate method. These catalysts are assessed for single-cell operation in an MEA including a Sustainion™ anion-exchange membrane. The electrochemical polarization shows a current density of 650 mA cm−2 at 2 V and 50 °C for the Ni1Fe1 anode composition. A durability test of 500 h is carried out using potential cycling as an accelerated stress-test. This shows a decrease in current density of 150 mA cm−2 mainly during the first 400 h. The performance achieved for the anion-exchange membrane electrolyser single-cell based on the NiFeOx catalyst appears promising. However, further improvements are required to enhance the stability under these operating conditions.

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