Article
Engineering, Chemical
Xiaomeng Chu, Jiaye Liu, Shasha Miao, Lei Liu, Yingda Huang, Erjun Tang, Shaojie Liu, Xuteng Xing, Nanwen Li
Summary: The functionality of side-chains plays a critical role in the performance of anion exchange membrane (AEM) materials, with longer side-chains enhancing alkali stability and conductivity, while side-chains containing triazole groups can promote the formation of hydrogen-bond networks to improve ion transport. The AEMs with longer side-chains showed excellent stability under alkaline conditions, and the AEMFC using these side-chain type AEMs achieved a peak power density of 141.3 mW cm(-2) at a current density of 320 mA cm(-2).
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Electrochemistry
Yang Hu, Jens Oluf Jensen, Patrick Bretzler, Lars Nilausen Cleemann, Jianan Yu, Qingfeng Li
Summary: This work investigated the stability of the Pt/C reference catalyst for the oxygen reduction reaction, establishing a reliable benchmark under controlled conditions and identifying the influence of experimental errors on the test results. The proposed experimental procedure could serve as a general reference for determining the stability of electrocatalysts for different electrochemical systems.
ELECTROCHIMICA ACTA
(2021)
Article
Materials Science, Multidisciplinary
Sambit Roy, Bholanath Ghanti, Debanjali Ghosh, Debabrata Pradhan, Brigitte Voit, Susanta Banerjee
Summary: Semifluorinated sulfonated polytriazoles exhibit enhanced proton conductivity and chemical stability, making them promising materials for proton exchange membranes in fuel cell applications. These membranes possess good mechanical properties, thermal stability, and can achieve both proton conduction and high power density.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Changjin Xu, Yue Zhang, Jing Chen, Song Li, Ya-Wen Zhang, Gaowu Qin
Summary: Noble metal Pt nanocatalysts with unique triple-junction structure exhibit enhanced catalytic stability and high activity for CO oxidation at mild temperatures, attributed to electron donation from graphitized carbon and confinement effect from high-density nanopores of the CeO2 support. Triple-junction Pt-C-CeO2 structure provides new inspiration for high-performance nanocatalyst fabrication.
SCIENCE CHINA-MATERIALS
(2021)
Article
Engineering, Chemical
Karam Yassin, Igal G. Rasin, Simon Brandon, Dario R. Dekel
Summary: This study investigates the relationship between AEMFC performance and key AEM properties using a numerical model. The findings show that membrane maximum hydration level has the greatest impact on AEMFC lifetime, followed by membrane ion-exchange capacity, water diffusivity, and membrane thickness. Improving the stability of the functional group is crucial for enhancing AEMFC lifetime, while AEM hydroxide conductivity has a negligible effect. The study provides algebraic functional relationships between key dimensionless parameters and a machine learning-based analysis of the relationship between AEM parameters and AEMFC lifetime.
JOURNAL OF MEMBRANE SCIENCE
(2024)
Article
Polymer Science
Gautam Das, Ji-Hyeok Choi, Phan Khanh Thinh Nguyen, Dong-Joo Kim, Young Soo Yoon
Summary: The fuel cell industry is highly promising for developing clean and sustainable energy generation. While significant progress has been made in proton exchange membrane fuel cells (PEMFCs), technical limitations and high costs remain. Anion exchange membrane fuel cells (AEMFCs) have emerged as a low-cost alternative, with numerous studies investigating their potential to overcome the challenges faced by PEMFCs.
Article
Chemistry, Physical
Ye Peng, Ja-Yeon Choi, Liliang Tian, Kyoung Bai, Yi Zhang, Dongchu Chen, Jianhuang Zeng, Dustin Banham
Summary: The distribution of platinum group metal (PGM) nanoparticle catalysts in the carbon support significantly affects the catalyst's performance. The placement of Pt either on the outer surface or within the pores of the carbon results in different activity and performance at high current densities. To gain further insight into the catalyst's properties, a relationship between Pt distribution and relative humidity (RH) tolerance is explored. This work provides valuable information for MEA designers in selecting catalysts for specific applications.
JOURNAL OF POWER SOURCES
(2022)
Article
Biochemistry & Molecular Biology
Roy J. B. M. Delahaije, Peter A. Wierenga
Summary: This study investigates the relationship between the exposed hydrophobicity and foam ability and stability using lysozyme variants with altered hydrophobicity. The results show that increasing hydrophobicity enhances foam ability and adsorption rate constant, but at higher relative exposed hydrophobicity, they become independent. Foam stability is affected by the initial foam structure, but in the protein-rich regime, it is not affected by hydrophobicity. The study confirms the similarity between protein-stabilized foams and emulsions and suggests that the model proposed for emulsions can be used to predict foam properties.
Article
Chemistry, Physical
Sandip Pal, Arani Choudhury, Pratyush Patnaik, Suman Sarkar, Uma Chatterjee
Summary: The objective of this work is to prepare functional copolymer/GO composite membranes by a simple and cost-effective method, and evaluate their structural, thermal, mechanical, and fuel cell performance. The results show that the addition of GO significantly enhances the mechanical properties and thermal stability of the composite membranes, while maintaining low methanol permeability and high ion conductivity.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Nanoscience & Nanotechnology
Hui-Yun Jeong, Dong-Gun Kim, Shedrack G. Akpe, Vinod K. Paidi, Hyun S. Park, Soo-Hyoung Lee, Kug-Seung Lee, Hyung Chul Ham, Pil Kim, Sung Jong Yoo
Summary: A simple wet-chemical route was developed to prepare core-shell-structured catalysts with high oxygen reduction reaction (ORR) activity using a low Pt loading amount. The thin Pt layer on Ni3N nanoparticles exhibited 5 times higher mass activity and specific activity than that of commercial Pt/C. This method can be utilized to prepare various transition-metal-based core-shell nanocatalysts for energy conversion reactions.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Analytical
Saja Haj-Bsoul, John R. Varcoe, Dario R. Dekel
Summary: One significant barrier in developing durable anion-exchange membranes for fuel cells and water electrolyzers is their limited chemical stability to alkali. The commonly used ex-situ tests do not adequately simulate the actual operando conditions, yielding misleading degradation rates. The study introduces a unique ex-situ method for determining the alkaline stability of AEMs under in-situ operating environments and provides stability trends for various AEM compositions.
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
(2022)
Review
Engineering, Chemical
Yaroslav Kobzar, Kateryna Fatyeyeva, Corinne Chappey, Nicolas Desilles, Stephane Marais
Summary: Research on ion exchange membrane for fuel cell technology has increased significantly in recent years, particularly for low-temperature operation. Polyoxadiazoles (PODs), as a class of heterocyclic polymers, exhibit unique thermal, mechanical, and chemical properties that make them promising for fuel cell applications. Various methods of POD synthesis and the development of POD-based composite membranes have been discussed to understand the structure/properties relationship.
REVIEWS IN CHEMICAL ENGINEERING
(2022)
Review
Chemistry, Physical
Changming Ding, Zhiyong Qiao
Summary: Fuel cells are emerging as alternative energy conversion and portable devices with highly efficient production of electrical energy and high-power density. However, issues with ion-exchange membranes, such as high cost and fuel crossover dehydration, have limited commercialization. Advanced PVA-based membranes show great promise as alternative ion-exchange membranes for fuel cells.
Article
Thermodynamics
Xingyi Shi, Yining Ma, Xiaoyu Huo, Oladapo Christopher Esan, Liang An
Summary: The thickness of the ion exchange membrane in liquid fuel cells has a critical impact on cell performance, with thinner membranes such as Nafion 211 being preferred for achieving high peak power density, while thicker membranes like Nafion 117 provide lower self-discharge rates for the cell.
INTERNATIONAL JOURNAL OF GREEN ENERGY
(2021)
Article
Polymer Science
Dong Pan, Si Chen, Patric Jannasch
Summary: Poly(xanthene)s (PXs) with trimethylammonium, methylpiperidinium, and quinuclidinium cations were synthesized and studied as anion exchange membranes (AEMs). These AEMs exhibited high ionic conductivity, thermal stability, and alkali-resistance, making them suitable for alkaline fuel cells and electrolyzers. The polymer architecture with a rigid PX backbone decorated with cations via flexible alkyl spacer chains contributed to these excellent properties.
Article
Electrochemistry
Roberta Sibul, Elo Kibena-Poldsepp, Sander Ratso, Mati Kook, Moulay Tahar Sougrati, Maike Kaarik, Maido Merisalu, Jaan Aruvali, Paarn Paiste, Alexey Treshchalov, Jaan Leis, Vambola Kisand, Vaino Sammelselg, Steven Holdcroft, Frederic Jaouen, Kaido Tammeveski
Review
Energy & Fuels
Danielle A. Salvatore, Christine M. Gabardo, Angelica Reyes, Colin P. O'Brien, Steven Holdcroft, Peter Pintauro, Bamdad Bahar, Michael Hickner, Chulsung Bae, David Sinton, Edward H. Sargent, Curtis P. Berlinguette
Summary: New technologies are needed to efficiently convert carbon dioxide into fuels and chemicals at near-ambient temperatures and pressures. Anion exchange membranes in zero-gap reactors show promise for mediating the electrochemical CO2 reduction reaction, but challenges remain in tailoring these membranes to meet the requirements of CO2RR systems.
Article
Nanoscience & Nanotechnology
Amelia Hohenadel, Apurva Shantilal Gangrade, Steven Holdcroft
Summary: A novel spectroelectrochemical approach was used to explore the water dissociation potentials and their relationship with current-voltage curve characteristics in bipolar membranes. The experiments showed that water dissociation occurs within BPM, with the resulting pH change measured using a UV/vis spectrometer.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Chemical
Apurva Shantilal Gangrade, Simon Cassegrain, Prakash Chandra Ghosh, Steven Holdcroft
Summary: This work investigates the permselectivity and transport properties of an ionene-based anion exchange membrane, finding that thicker membranes exhibit higher permselectivity and fixed charge group concentration, leading to better performance. The permselectivity and specific area conductivity of Aemion AEMs were determined by their fixed charge group concentration, with the AF1-HNN5-50 membrane showing comparable performance to the common anion exchange membrane Selemion AMV.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Article
Chemistry, Physical
Peter Mardle, Simon Cassegrain, Faezeh Habibzadeh, Zhiqing Shi, Steven Holdcroft
Summary: The study demonstrates the importance of anolyte concentration and volume in determining the energetic conversion efficiency of a room-temperature zero-gap, KOH anolyte CO2 electrolyzer. Carbonate ion crossover is shown to significantly impact the ECell during continuous operation. Thicker and/or lower ion-exchange capacity variant membranes can reduce carbonate ion crossover by approximately 20%, which is crucial for the economic viability of direct CO2 electrolysis systems. Future membrane designs should focus on reducing carbonate crossover without compromising electrolyzer efficiency and stability.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Emmanuel Balogun, Simon Cassegrain, Peter Mardle, Michael Adamski, Torben Saatkamp, Steven Holdcroft
Summary: This study reports the design and addition of HB-sPPT-H+ ionomer particles to improve the performance of proton exchange membrane fuel cells. By introducing a direct pathway for proton conduction, the ionic resistance of the catalyst layer is reduced, catalyst mass activity is increased, and power output is improved.
ACS ENERGY LETTERS
(2022)
Article
Chemistry, Physical
Binyu Chen, Peter Mardle, Steven Holdcroft
Summary: Anion exchange membrane water electrolyzers (AEMWEs) are potential for green hydrogen production. A study found that using 1M KOH electrolyte at 60℃ and coating the membrane with a HMT-PMBI catalyst can improve the stability of the electrolyzer. Reducing the KOH concentration or using pure water decreases the voltage stability, possibly due to increased swelling. Introducing a crosslinked derivative of the HMT-PMBI membrane reduces swelling and enhances the stability of the system.
JOURNAL OF POWER SOURCES
(2022)
Article
Electrochemistry
Xin Wang, Peter Mardle, Michael Adamski, Binyu Chen, Steven Holdcroft
Summary: In this study, fully hydrocarbon-based ionomer catalyst coated membranes (CCMs) were evaluated in a proton exchange membrane water electrolyzer cell. The results showed that sPPB-H+ membranes required a lower applied potential compared to the reference Nafion NR112 recast membranes. Although the sPPB-H+ membranes initially had lower gas crossover, the gas crossover increased and higher rates of voltage evolution were observed during stability tests. The use of sPPB-H+ as the catalyst layer binder also showed higher efficiency when the ionomer content was 20 wt%.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Lisa Royer, Antoine Bonnefont, Tristan Asset, Benjamin Rotonnelli, Juan-Jesus Velasco-Velez, Steven Holdcroft, Simon Hettler, Raul Arenal, Benoit Pichon, Elena Savinova
Summary: Transition metal oxides show promise as cost-effective catalysts for oxygen evolution reaction (OER) in alkaline media. However, understanding the transformations occurring under harsh oxidative OER conditions is crucial for developing stable and active catalysts. This study used NEXAFS spectroscopy to investigate the redox transformations of core-shell Fe3O4@CoFe2O4 oxide nanoparticles over a range of potentials. The analysis revealed that the Fe3O4 core significantly influences the surface chemistry of the CoFe2O4 shell during OER, with the Co (II) structure preserved even at high potentials where Co (II) is expected to be oxidized into Co (III), while Fe (II) in the core undergoes reversible oxidation to Fe (III).
Article
Chemistry, Physical
Emmanuel Balogun, Steven Holdcroft
Summary: Choosing the appropriate conditioning method is crucial for improving the performance and durability of freshly prepared fuel cell membrane-electrode-assemblies (MEA). This study investigates the impact of different conditioning protocols on hydrocarbon solid polymer electrolyte-based MEAs and finds that the cathode starvation protocol leads to the highest peak power density and the lowest performance losses during durability testing.
JOURNAL OF POWER SOURCES
(2023)
Article
Polymer Science
Philip Overton, Anastasiia Konovalova, Kate Fraser, Steven Holdcroft
Summary: In this study, the first AB-type primary-chain poly-(arylimidazole) (AB-PAI) homopolymers were synthesized by Debus-Radziszewski polycondensation, providing evidence for the Carothers' Step-Growth mechanism. The quaternization of imidazole units in AB-PAI resulted in statistical poly(arylimidazolium) (AB-PAIm) ionenes. The thermally stable AB-PAI and AB-PAIm showed high resistance to degradation and can be solvated by polar organic solvents.
Article
Chemistry, Physical
Binyu Chen, Ana Laura G. Biancolli, Chase L. Radford, Steven Holdcroft
Summary: Anion-exchange membrane water electrolysis (AEMWE) is a promising technology for low-cost, high-efficiency, green hydrogen production. The use of stainless steel (SS) felt as a combined oxygen evolution reaction (OER) electrocatalyst and porous transport layer simplifies the study of AEMs in water electrolyzers. In situ studies of OER electrocatalysts and catalyst layer compositions should be performed with Ni felt to reduce OER contributions from the porous transport layer.
ACS ENERGY LETTERS
(2023)
Article
Electrochemistry
Ana Laura G. Biancolli, Anastasiia Konovalova, Elisabete I. Santiago, Steven Holdcroft
Summary: Ex-situ characterization of solid polymer electrolytes is important for their development in energy applications, with a focus on quantifying ionic conductivity. Conventional measurements often require free-standing polymer films, which may be difficult to fabricate, necessitating the need for quantification in powder form. This study presents a practical method using a modified through-plane cell configuration to measure the ionic conductivity of solid polymer electrolytes in powder form. Two types of insoluble polymer electrolytes were tested, with measured ionic conductivity values presented.
INTERNATIONAL JOURNAL OF ELECTROCHEMICAL SCIENCE
(2023)
Article
Engineering, Chemical
Apurva Shantilal Gangrade, Beatriz Tusi, Prakash Chandra Ghosh, Steven Holdcroft
Summary: This study investigates the monovalent/divalent ion permselectivity of anion exchange ionenes, a type of solid polymer polyelectrolytes. The results show that thicker ionenes with lower ion exchange capacity exhibit higher permselectivity. Thinner membranes lead to a greater ionic flux loss and decreased permselectivity, particularly for lower ion exchange capacity membranes. Surprisingly, commercial Selemion AMV has lower permselectivity than low ion exchange capacity ionene-based Aemion (R) AEMs, which can be attributed to the highly tortuous internal morphology of low water content ionenes. The permselectivity-to-resistance ratio values are higher for low ion exchange capacity ionenes compared to high ion exchange capacity ionenes and Selemion AMV.
JOURNAL OF MEMBRANE SCIENCE
(2023)
Review
Materials Science, Multidisciplinary
Michael Adamski, Nicolas Peressin, Steven Holdcroft
Summary: The recent expansion in proton exchange membrane (PEM) research corresponds with the growth of PEM fuel cell research. Despite concerns with PFSA, hydrocarbon membranes are gaining attention for their lower gas permeability and stability, with sulfonated polyphenylenes being leading candidates.
MATERIALS ADVANCES
(2021)
