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

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1720
Author(s):  
Sabrina Campagna Zignani ◽  
Massimiliano Lo Faro ◽  
Stefano Trocino ◽  
Antonino Salvatore Aricò
Keyword(s):  
Single Cell ◽  
Anion Exchange ◽  
Oxygen Evolution ◽  
Current Density ◽  
Electrochemical Behaviour ◽  
Stress Test ◽  
Supporting Electrolyte ◽  
Anion Exchange Membrane ◽  
Operating Conditions ◽  
Exchange Membrane

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.

High-performance anion exchange membrane alkaline seawater electrolysis

2021 ◽  
Author(s):  
Yoo Sei Park ◽  
Jooyoung Lee ◽  
Myeong-Je Jang ◽  
Juchan Yang ◽  
Jae Hoon Jeong ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Performance ◽  
Anion Exchange Membrane ◽  
Hydrogen Energy ◽  
Highly Active ◽  
Production Of Hydrogen ◽  
Exchange Membrane ◽  
Seawater Electrolysis

Seawater electrolysis is a promising technology for the production of hydrogen energy and seawater desalination. To produce hydrogen energy through seawater electrolysis, highly active electrocatalysts for the oxygen evolution reaction...

Degradation study for membrane electrode assembly of anion exchange membrane fuel cell at a single-cell level

2021 ◽  
Author(s):  
Jonghyun Hyun ◽  
Seok-Hwan Yang ◽  
Gisu Doo ◽  
Sungyu Choi ◽  
Dong-Hyun Lee ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Single Cell ◽  
Anion Exchange ◽  
Membrane Electrode Assembly ◽  
Anion Exchange Membrane ◽  
Membrane Electrode ◽  
Single Cell Level ◽  
Cell Level ◽  
Degradation Study ◽  
Exchange Membrane

The durability of the membrane electrode assembly (MEA) is one of the important requirements for the successful commercialization of anion exchange membrane fuel cells (AEMFCs). While chemical stabilities of the...

scholarly journals Viologen-Decorated TEMPO for Neutral Aqueous Organic Redox Flow Batteries

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Shuzhi Hu ◽  
Liwen Wang ◽  
Xianzhi Yuan ◽  
Zhipeng Xiang ◽  
Mingbao Huang ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Supporting Electrolyte ◽  
Linear Sweep Voltammetry ◽  
High Energy ◽  
Crystal Structure Analysis ◽  
Anion Exchange Membrane ◽  
High Energy Density ◽  
Favorable Effect ◽  
Flow Battery ◽  
Exchange Membrane

A novel electroactive organic molecule, viz., 1-(1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)-1′-(3-(trimethylammonio)propyl)-4,4′-bipyridinium trichloride ((TPABPy)Cl3), is synthesized by decorating 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) with viologen, which is used as the positive electrolyte in neutral aqueous redox flow battery (ARFB). Extensive characterizations are performed to investigate the composition/structure and the electrochemical behavior, revealing the favorable effect of introducing the cationic viologen group on the electroactive TEMPO. Salient findings are as follows. First, the redox potential is elevated from +0.745 V for TEMPO to +0.967 V for decorated TEMPO, favoring its use as the positive electrolyte. Such an elevation originates from the electron-withdrawing effect of the viologen unit, as evidenced by the nuclear magnetic resonance and single crystal structure analysis. Second, linear sweep voltammetry reveals that the diffusion coefficient is 2.97×10−6 cm2 s−1, and the rate constant of the one-electron transfer process is 7.50×10−2 cm s−1. The two values are sufficiently high as to ensure low concentration and kinetics polarization losses during the battery operation. Third, the permeability through anion-exchange membrane is as low as 1.80×10−11 cm2 s−1. It is understandable as the positive-charged viologen unit prevents the molecule from permeating through the anion exchange membrane by the Donnan effect. Fourth, the ionic nature features a decent conductivity and thus eliminates the use of additional supporting electrolyte. Finally, a flow battery is operated with 1.50 M (TPABPy)Cl3 as the positive electrolyte, which affords a high energy density of 19.0 Wh L-1 and a stable cycling performance with capacity retention of 99.98% per cycle.

Superior performance and stability of anion exchange membrane water electrolysis: pH-controlled copper cobalt oxide nanoparticles for the oxygen evolution reaction

2020 ◽  
Vol 8 (8) ◽  
pp. 4290-4299 ◽  
Author(s):  
Myeong Je Jang ◽  
Juchan Yang ◽  
Jongmin Lee ◽  
Yoo Sei Park ◽  
Jaehoon Jeong ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Anion Exchange ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Water Electrolysis ◽  
Anion Exchange Membrane ◽  
Superior Performance ◽  
Oxide Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Exchange Membrane

Cu0.5Co2.5O4 nanoparticles are obtained by changes in the pH and applied as the anode in anion exchange membrane water electrolysis.

scholarly journals Effect of Copper Cobalt Oxide Composition on Oxygen Evolution Electrocatalysts for Anion Exchange Membrane Water Electrolysis

2020 ◽  
Vol 8 ◽  
Author(s):  
Chae-Yeon Kwon ◽  
Jae-Yeop Jeong ◽  
Juchan Yang ◽  
Yoo Sei Park ◽  
Jaehoon Jeong ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Anion Exchange ◽  
Oxygen Evolution ◽  
Active Sites ◽  
Anion Exchange Membrane ◽  
Electrochemical Kinetics ◽  
Precipitation Method ◽  
Energetic Efficiency ◽  
Co Precipitation ◽  
Exchange Membrane

Copper cobalt oxide nanoparticles (CCO NPs) were synthesized as an oxygen evolution electrocatalyst via a simple co-precipitation method, with the composition being controlled by altering the precursor ratio to 1:1, 1:2, and 1:3 (Cu:Co) to investigate the effects of composition changes. The effect of the ratio of Cu2+/Co3+ and the degree of oxidation during the co-precipitation and annealing steps on the crystal structure, morphology, and electrocatalytic properties of the produced CCO NPs were studied. The CCO1:2 electrode exhibited an outstanding performance and high stability owing to the suitable electrochemical kinetics, which was provided by the presence of sufficient Co3+ as active sites for oxygen evolution and the uniform sizes of the NPs in the half cell. Furthermore, single cell tests were performed to confirm the possibility of using the synthesized electrocatalyst in a practical water splitting system. The CCO1:2 electrocatalyst was used as an anode to develop an anion exchange membrane water electrolyzer (AEMWE) cell. The full cell showed stable hydrogen production for 100 h with an energetic efficiency of >71%. In addition, it was possible to mass produce the uniform, highly active electrocatalyst for such applications through the co-precipitation method.

scholarly journals In-Situ Combination of Bipolar Membrane Electrodialysis with Monovalent Selective Anion-Exchange Membrane for the Valorization of Mixed Salts into Relatively High-Purity Monoprotic and Diprotic Acids

Membranes ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 135 ◽  
Author(s):  
Haiyang Yan ◽  
Wei Li ◽  
Yongming Zhou ◽  
Muhammad Irfan ◽  
Yaoming Wang ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Current Density ◽  
High Purity ◽  
Anion Exchange Membrane ◽  
Discharge Process ◽  
Bipolar Membrane ◽  
Liquid Discharge ◽  
Bipolar Membrane Electrodialysis ◽  
Mixed Salts ◽  
Exchange Membrane

The crystalized mixed salts from the zero liquid discharge process are a hazardous threat to the environment. In this study, we developed a novel electrodialysis (SBMED) method by assembling the monovalent selective anion-exchange membrane (MSAEM) into the bipolar membrane electrodialysis (BMED) stack. By taking the advantages of water splitting in the bipolar membrane and high perm-selectivity of MSAEM for the Cl− ions against the SO42− ions, this combination allows the concurrent separation of Cl−/SO42− and conversion of mixed salts into relatively high-purity monoprotic and diprotic acids. The current density has a significant impact on the acid purity. Both the monoprotic and diprotic acid purities were higher than 80% at a low current density of 10 mA/cm2. The purities of the monoprotic acids decreased with an increase in the current density, indicating that the perm-selectivity of MSAEM decreases with increasing current density. An increase in the ratio of monovalent to divalent anions in the feed was beneficial to increase the purity of monoprotic acids. High-purity monoprotic acids in the range of 93.9–96.1% were obtained using this novel SBMED stack for treating simulated seawater. Therefore, it is feasible for SBMED to valorize the mixed salts into relatively high-purity monoprotic and diprotic acids in one step.

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

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Dirk Henkensmeier ◽  
Malikah Najibah ◽  
Corinna Harms ◽  
Jan Žitka ◽  
Jaromír Hnát ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Water Electrolysis ◽  
Anion Exchange Membrane ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Alkaline Water Electrolysis ◽  
Chemical Structures ◽  
Technical Requirements ◽  
Target Values ◽  
Exchange Membrane

Abstract One promising way to store and distribute large amounts of renewable energy is water electrolysis, coupled with transport of hydrogen in the gas grid and storage in tanks and caverns. The intermittent availability of renewal energy makes it difficult to integrate it with established alkaline water electrolysis technology. Proton exchange membrane (PEM) water electrolysis (PEMEC) is promising, but limited by the necessity to use expensive platinum and iridium catalysts. The expected solution is anion exchange membrane (AEM) water electrolysis, which combines the use of cheap and abundant catalyst materials with the advantages of PEM water electrolysis, namely, a low foot print, large operational capacity, and fast response to changing operating conditions. The key component for AEM water electrolysis is a cheap, stable, gas tight and highly hydroxide conductive polymeric AEM. Here, we present target values and technical requirements for AEMs, discuss the chemical structures involved and the related degradation pathways, give an overview over the most prominent and promising commercial AEMs (Fumatech Fumasep® FAA3, Tokuyama A201, Ionomr Aemion™, Dioxide materials Sustainion®, and membranes commercialized by Orion Polymer), and review their properties and performances of water electrolyzers using these membranes.

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