Article
Nanoscience & Nanotechnology
Masashi Harada, Hiroaki Kadoura, Shin-ichi Takata, Hiroki Iwase, Shuji Kajiya, Takahisa Suzuki, Naoki Hasegawa, Akihiro Shinohara, Satoru Kato
Summary: The performance of a polymer electrolyte fuel cell can be enhanced by improving the proton conductivity of the catalyst layer, which is influenced by both ionomer content and carbon support. A novel proton conductivity model is introduced to simulate catalyst layers with different amounts of ionomers and carbon types. The model considers the presence of thin-film ionomers with suppressed proton conductivities and suggests that reducing the fraction of thin-film ionomers or avoiding factors that suppress their proton conduction improves the performance of the catalyst layer.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Biochemistry & Molecular Biology
Beom-Seok Kim, Jong-Hyeok Park, Jin-Soo Park
Summary: In this study, blended PFSA ionomers with different equivalent weights were prepared and studied for their applications in fuel cells. The results showed that blended ionomers exhibited higher ion conductivity and proton conduction ability, resulting in improved fuel cell performance.
Article
Chemistry, Physical
Haruhiko Shintani, Nobuhiro Miyata, Yasushi Sugawara
Summary: The study found that the particle size of mesoporous carbons significantly affects the performance of catalysts in polymer electrolyte fuel cells, with the optimal polarization performance achieved at a particle size of 695 nm. The oxygen reduction reaction activity of Pt/MPCs increases with the size of the mesoporous carbon particles, and the internal structure also significantly impacts the activity.
JOURNAL OF POWER SOURCES
(2021)
Article
Electrochemistry
Nancy N. Kariuki, Andrew T. Haug, Jae H. Park, Matthew J. Lindell, Deborah J. Myers
Summary: Ultra-small angle X-ray scattering technique was used to investigate the effects of carbon support type, presence of platinum, and ionomer loading on the microstructure of polymer electrolyte fuel cell catalyst layers. It was found that carbon type, platinum presence, and ionomer loading significantly impact carbon agglomeration, which in turn affects electrode performance.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Andrea Perego, Arezoo Avid, Divija N. Mamania, Yechuan Chen, Plamen Atanassov, Hakan Yildirim, Madeleine Odgaard, Iryna V. Zenyuk
Summary: The evolution of ionomer-Pt and ionomer-carbon interfaces during the life cycle of PEFCs has a significant impact on the fuel cell performance. Catalyst and carbon support accelerated stress tests show that the location and contact degree of Pt nanoparticles with ionomer greatly affect the surface area loss of the electrode under different gas flow conditions. The selection of support materials also has a significant impact on ionomer degradation and electrode surface area maintenance.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Chemistry, Physical
Masashi Harada, Shuji Kajiya, Takuya Mitsuoka, Shin-ichi Takata, Hiroki Iwase, Hiroyuki Aoki
Summary: The catalyst layers in polymer electrolyte fuel cells have a hierarchical porous structure consisting of Pt-loaded carbon (Pt/C) particles and ionomer molecules, which significantly influence their performance. The composition of the solvent used for coating the dispersion of Pt/C and ionomer is critical but its effects on catalyst layer performance are unknown. This study investigates different catalyst layers formed with dispersions using a water-ethanol solvent with varying water fractions, and reveals that the solvent-related differences minimally affect the catalyst layer performance but marginally change the hierarchical structure of the ionomer, resulting in a robust performance with tunable dispersion structures.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Chemistry, Physical
Hong Ren, Xiangchao Meng, Yongli Lin, Xiaojin Li, Zhigang Shao
Summary: The surface enrichment process of ionomer during the drying of catalyst ink film was investigated. Two ionomer enrichment mechanisms were proposed based on the alcohol content of the ink. The enrichment of ionomer reduces oxygen transport resistance and improves proton conduction.
JOURNAL OF POWER SOURCES
(2023)
Article
Electrochemistry
Wataru Yoshimune, Masashi Harada
Summary: This study investigated the effects of temperature on the nanostructures of catalyst inks fabricated from surface-modified carbon supports without platinum nanoparticles. The thickness of the shell ionomer layer at 70 degrees Celsius was found to be twice that at 25 degrees Celsius, and shear-thinning behavior was observed at elevated temperatures. Plausible factors in the shear-thinning behavior were a reduction in electrostatic repulsion and the appearance of bridging attraction.
ELECTROCHEMISTRY COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Yeonghwan Fang, Changwook Seol, Sang Moon Kim, Segeun Jang
Summary: This study investigates the correlation effect of catalyst loading and ionomer content on the performance of polymer electrolyte membrane water electrolysis (PEMWE). The effects on kinetic, ohmic, and mass transfer overpotential are estimated and analyzed. A critical ionomer concentration is proposed, and high-performance PEMWE is achieved.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Hong Ren, Xiangchao Meng, Yongli Lin, Zhigang Shao
Summary: The study suggests that catalyst inks containing long-side-chain ionomers show better structural stability after storage compared to those containing short-side-chain ionomers, making it easier to regain initial ink properties.
JOURNAL OF POWER SOURCES
(2022)
Article
Nanoscience & Nanotechnology
Junmo Koo, Heon Jun Jeong, Wonjoon Choi, Joon Hyung Shim
Summary: Platinum-carbon nanotube (CNT) catalysts were evaluated as cathode catalysts for polymer electrolyte membrane fuel cells. Pt catalysts were fabricated using atomic layer deposition on bare or O2 plasma treated CNTs. The morphology of the Pt particles differed on the two types of CNT supports, leading to differences in electrochemical and fuel cell performance. Factors other than geometric features also influenced fuel cell performance.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Chi-Young Jung, Seo-Won Choi, Won-Young Choi, Chae-Won Hong, Vasanth Rajendiran Jothi, Sung-Chul Yi
Summary: The proposed electrode architecture with infinitesimally thin ionomer deposited onto Pt using electrostatic spray deposition under hot and humid environments significantly improves mass activity, cell performance, and stability towards carbon degradation, surpassing the state-of-the-art decal-transferred electrode in a cost-effective and scalable manner, thereby paving the way for sustainable hydrogen mobility on a global scale.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Physical
Hong Ren, Yue Teng, Xiangchao Meng, Dahui Fang, He Huang, Jiangtao Geng, Zhigang Shao
Summary: This study investigates the performance and internal mechanism of SSC PFSA ionomers in proton exchange membrane fuel cells, revealing the correlation between the distribution of different EW ionomers in CL and their performance. By increasing IEC and reducing ionomer adsorption on Pt/C, the formation of Pt/C-ionomer connection network is facilitated, leading to a more uniform ionomer proton conduction network in the CL.
JOURNAL OF POWER SOURCES
(2021)
Article
Nanoscience & Nanotechnology
Yuqing Guo, Daozeng Yang, Bing Li, Daijun Yang, Pingwen Ming, Cunman Zhang
Summary: This study investigated the effects of the dielectric constant of a dispersion solvent and ionomer content on the rheology of graphitized carbon-supported Pt catalyst ink and the structure of catalyst layers. Increasing the solvent epsilon or ionomer content affected the zeta potential of catalyst particles in the ink and altered the internal interaction, leading to changes in ink rheology. Higher solvent epsilon enhanced ionomer adsorption onto catalysts, improving adhesion between ink particles and reducing CL cracking. Increasing ionomer content also increased fracture toughness of CLs, decreasing crack width.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Sarah A. Berlinger, Bryan D. McCloskey, Adam Z. Weber
Summary: The interaction between ionomer and catalyst particles in porous electrodes of electrochemical-energy-conversion devices is crucial for performance, with ionomer adsorption being influenced mainly by entropic interactions with the carbon surface. Solvents with higher water content promote ionomer adsorption, and ionomer dispersions change with time, leading to dynamic binding interactions.
ACS ENERGY LETTERS
(2021)
Article
Electrochemistry
Shuiyun Shen, Ziwen Ren, Silei Xiang, Shiqu Chen, Zehao Tan, Huiyuan Li, Junliang Zhang
Summary: Proton exchange membrane fuel cell (PEMFC), with its high power density, high energy density, and low operating temperature, plays a crucial role in energy saving, emission reduction, and the development of new energy vehicles. However, the mass production of PEMFC is hindered by the rarity and cost of Pt resource, which calls for the development of highly active and durable non-precious metal catalysts. In this study, a highly active and durable Fe-N-C catalyst was derived from metal-organic framework (MOF) materials, showing comparable performance to commercial Pt/C catalyst in the oxygen reduction reaction (ORR). Its good stability in both rotating disk electrode (RDE) and single-cell tests indicates its potential in replacing Pt catalyst as the ORR electrocatalyst in fuel cells.
JOURNAL OF ELECTROCHEMICAL ENERGY CONVERSION AND STORAGE
(2022)
Article
Chemistry, Multidisciplinary
Xiyang Cai, Fan Yang, Lu An, Cehuang Fu, Liuxuan Luo, Shuiyun Shen, Junliang Zhang
Summary: Researchers have intensively investigated the electrochemical nitrogen reduction reaction (NRR) as a potential next-generation technology for ammonia production. They found that no discernible amount of ammonia was detected in either acidic or alkaline solutions when evaluating the performance of commercial noble metal nanocatalysts. An effective method was proposed to remove pre-existing pollutants by consecutive cyclic voltammetry scans, ensuring reliable and reproducible results.
Review
Chemistry, Physical
Huiyuan Li, Xiaojing Cheng, Xiaohui Yan, Shuiyun Shen, Junliang Zhang
Summary: This review comprehensively explores the influences of key materials degradation in membrane electrode assemblies (MEAs) on oxygen transport resistance in proton exchange membrane fuel cells (PEMFCs). The study finds that carbon corrosion in cathode catalyst layers (CCLs) leads to pore structure destruction and impact on ionomer distribution, catalyst degradation increases the local oxygen transport resistance, degradation of ionomer changes its structure and worsens the local oxygen transport, and loss of carbon and PTFE in gas diffusion layers (GDLs) results in higher hydrophilicity and increased oxygen transport resistance.
Article
Chemistry, Multidisciplinary
Liuxuan Luo, Cehuang Fu, Yangge Guo, Xiyang Cai, Xiashuang Luo, Zehao Tan, Rui Xue, Xiaojing Cheng, Shuiyun Shen, Junliang Zhang
Summary: Rationally combining designed supports and metal-based nanomaterials is effective to synergize their respective physicochemical and electrochemical properties for developing highly active and stable/durable electrocatalysts. In this work, sub-5 nm monodispersed nanodots with a special nanostructure are synthesized and anchored onto 3D porous N-doped graphene nanosheets. The resulting electrocatalysts exhibit exceptional activity and stability, outperforming commercial Pd/C and Pt/C. Advanced experimental and theoretical analyses reveal the synthetic mechanism and origins of the enhanced performance, providing a design paradigm for high-performance electrocatalysts.
Article
Engineering, Environmental
Liuxuan Luo, Zehao Tan, Cehuang Fu, Rui Xue, Xiaojing Cheng, Tianzi Bi, Lutian Zhao, Yangge Guo, Xiyang Cai, Jiewei Yin, Shuiyun Shen, Junliang Zhang
Summary: Increasing the accessible active sites and improving the intrinsic activity are effective strategies for enhancing the electrocatalytic activity of nanomaterials. In this study, highly uniform Pd nanotetrahedrons with Pt-doped surfaces are synthesized and supported onto carbon black, showing improved electrocatalytic performance.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Huiyuan Li, Jiabin You, Xiaojing Cheng, Xiaohui Yan, Shuiyun Shen, Junliang Zhang
Summary: This paper investigates the effects of Co2+ contamination on the structure of ionomer films and the corresponding local oxygen transport behavior in cathode catalyst layers (CCLs). The study finds that Co2+ contamination reduces water content and increases the modulus of the ultrathin ionomer film, while also affecting the aggregation size of the ionomer. Additionally, the contamination increases the local oxygen transport resistance and decreases the peak power density of the fuel cell.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Jing Li, Fan Yang, Min Jiang, Xiyang Cai, Qiaodan Hu, Junliang Zhang
Summary: The development of perovskite-type electrocatalysts with high activity, excellent durability, and affordable cost is important for promoting clean energy technologies. In this study, Bi(0.15)Sr(0.85)Co(1-x)FexO(3-delta) (x=0.2, 0.4, 0.6, 0.8, 1) perovskite materials were prepared and their OER electrocatalytic activity and durability were investigated. The results showed that the composition BiSC0.8F0.2 exhibited impressive electrocatalytic performances with low overpotential and excellent long-time durability.
CHEMICAL ENGINEERING JOURNAL
(2023)
Review
Chemistry, Physical
Shiqing Liu, Shu Yuan, Yuwei Liang, Huiyuan Li, Zhiling Xu, Qian Xu, Jiewei Yin, Shuiyun Shen, Xiaohui Yan, Junliang Zhang
Summary: Proton exchange membrane fuel cells (PEMFCs) are important for achieving decarbonized energy demand. However, their commercialization has been hindered by high costs. This paper focuses on reducing the amount of platinum (Pt) in PEMFCs to address the cost issue. Specifically, it summarizes various electrode design methods to optimize the local transport resistance of oxygen in the cathode catalyst layer (CCL). The insights provided in this paper offer recommendations for high-efficiency low-platinum fuel cell fabrication and design.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Electrical & Electronic
Longhai Zhang, Lina Ning, Xueqing Yang, Sheng Zeng, Tian Yuan, Gaopeng Li, Changchun Ke, Junliang Zhang
Summary: The fuel cell hybrid powertrain is a potential power supply system for fuel cell vehicles but faces the issue of excessive fuel consumption. In order to effectively manage fuel consumption, a power and control system for fuel cell city buses is proposed through simulation study and road test verifications. The research results show that the half-power prediction energy management strategy effectively reduces fuel consumption by 7.1% and battery cycle by 6.0% compared to the stepped management strategy of battery SOC.
AUTOMOTIVE INNOVATION
(2023)
Article
Nanoscience & Nanotechnology
Jiabin You, Zhifeng Zheng, Xiaojing Cheng, Huiyuan Li, Cehuang Fu, Liuxuan Luo, Guanghua Wei, Shuiyun Shen, Xiaohui Yan, Junliang Zhang
Summary: Understanding the oxygen transport mechanism through an ionomer film that covered the catalyst surface is essential for improving fuel cell performance. The effects of carbon supports on local transport are still unclear. This study investigates the local oxygen transports based on conventional solid carbon (SC) and high-surface-area carbon (HSC) supports.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Zhiling Xu, Shu Yuan, Lu An, Shuiyun Shen, Qian Xu, Xiaohui Yan, Junliang Zhang
Summary: One approach to improving the proton conductivity of nanoscale ultrathin Nafion films is by adjusting the catalyst-ionomer interaction. In this study, ultrathin films were prepared on SiO2 substrates with negative or positive surface charges. The results showed that the negatively charged substrate resulted in faster film formation and increased proton conductivity, while the positively charged substrate led to slower film formation and decreased proton conductivity. The interaction between surface charges and Nafion molecules affected molecular orientation, surface energy, and phase separation, influencing proton conductivity.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Review
Thermodynamics
Shu Yuan, Congfan Zhao, Xiyang Cai, Lu An, Shuiyun Shen, Xiaohui Yan, Junliang Zhang
Summary: This review discusses the evolution and transport processes of gas bubbles, as well as the mechanisms by which bubbles impact PEMWE cell performance. It also summarizes the latest methods to mitigate bubble-induced performance losses. Similarities between PEMWE and AEMWE are explored, and principles of bubble management are presented, along with future research priorities and suggestions.
PROGRESS IN ENERGY AND COMBUSTION SCIENCE
(2023)
Article
Chemistry, Physical
Yang Zhang, Yuanting Peng, Qiqi Wan, Donghao Ye, Ao Wang, Longhai Zhang, Wenxing Jiang, Yingying Liu, Jin Li, Xiaodong Zhuang, Junliang Zhang, Changchun Ke
Summary: A fuel cell based on B10H14 was studied, which achieved a peak power density of 110.82 mW/cm2, comparable to common DMFCs. The new fuel cell exhibited a higher open circuit voltage than DMFCs and other DLFCs, indicating that the Nafion membrane is effective in suppressing fuel crossover. This opens up a new way to utilize the chemical energy of B10H14 and develops a promising fuel cell for high specific energy applications.
MATERIALS TODAY ENERGY
(2023)
Article
Chemistry, Multidisciplinary
Xiyang Cai, Xingdian Li, Jiabin You, Fan Yang, Zulipiya Shadike, Song Qin, Liuxuan Luo, Yangge Guo, Xiaohui Yan, Shuiyun Shen, Guanghua Wei, Zhichuan Xu, Junliang Zhang
Summary: Ammonia plays a crucial role in fertilizer production and chemical synthesis, and it has the potential to be a carbon-free energy carrier in the future hydrogen economy. Lithium-mediated electrochemical nitrogen reduction (LiNR) has been recognized as a promising alternative to the conventional Haber-Bosch process due to its lower carbon emissions. While significant advancements have been made in LiNR performance through the exploration of lithium salts and proton donors, solvent research is still in its early stages. This study systematically investigates the use of ether-based solvents in LiNR, evaluating their conductivity, parasitic reactions, product distribution, and faradaic efficiency. The findings demonstrate that different solvent molecules impact LiNR characteristics by influencing the solvation configurations of conductive ions and inducing the formation of a solid electrolyte interphase with varying compositions. This research sheds light on the importance of solvents in LiNR and contributes to the optimization of electrolytes for improved performance.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
