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34 results on '"Guo, Yangge"'

13. Technical challenges and enhancement strategies for transitioning PEMFCs from H2-air to H2-O2

Author

Cheng, Ming, Liu, Mengjie, Feng, Yong, Guo, Yangge, Xu, Huahui, Luo, Liuxuan, Yin, Jiewei, Yan, Xiaohui, Shen, Shuiyun, Zhang, Junliang, Cheng, Ming, Liu, Mengjie, Feng, Yong, Guo, Yangge, Xu, Huahui, Luo, Liuxuan, Yin, Jiewei, Yan, Xiaohui, Shen, Shuiyun, and Zhang, Junliang

Abstract

Compared to other types of air-independent propulsion (AIP) technologies, proton exchange membrane fuel cells (PEMFCs) are gaining increasing recognition for applications in enclosed environments without air, such as underwater and aerospace scenarios. This is attributed to their large power density and silent operation. Although PEMFCs have reached a level of maturity in terrestrial applications nowadays, transitioning them from air supply (H2-air) to pure oxygen supply (H2-O2) still presents numerous technical challenges, as indicated by our literature review and analysis. These challenges primarily involve redesigning key materials, water and thermal management techniques, and system configurations at various scales, ranging from micro to macro levels. First, the oxygen-rich environments and higher operational voltage of H2-O2 PEMFCs will inevitably accelerate the corrosion rate of all PEMFCs components. Secondly, the active water and thermal management techniques adopted in H2-air PEMFCs no longer meet the requirements of energy efficiency and compactness in enclosed environments. Finally, current hydrogen sources technologies limit mission durations due to their relatively low energy storage density, and air compressors commonly used in H2-air PEMFCs are not compatible with H2-O2 PEMFCs. The nature of enclosed environments also necessitates more rigorous approaches to safety in system integration. This review systematically summarizes comprehensive enhancement strategies aimed at addressing these challenges. Developing anti-corrosive catalysts and supports in the catalyst layer, membrane, gas diffusion layer (GDL), and bipolar plate (BPP) can mitigate their degradation to prolong the lifespan of H2-O2 PEMFCs. Passive water and thermal management techniques are also essential for making PEMFCs practical in enclosed environments. Furthermore, advanced hydrogen and oxygen sources technologies are crucial for increasing energy storage density, and safety design is

Published
2024

21. Electronic and Potential Synergistic Effects of Surface-Doped P–O Species on Uniform Pd Nanospheres: Breaking the Linear Scaling Relationship toward Electrochemical Oxygen Reduction

Author

Luo, Liuxuan, primary, Fu, Cehuang, additional, Guo, Yangge, additional, Kang, Qi, additional, Wu, Aiming, additional, Cai, Xiyang, additional, Zhao, Lutian, additional, Tan, Zehao, additional, Yin, Jiewei, additional, Xia, Guofeng, additional, Shen, Shuiyun, additional, and Zhang, Junliang, additional

Published
2022
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33. Ultrafine Core@Shell Cu1Au1@Cu1Pd3Nanodots Synergized with 3D Porous N-Doped Graphene Nanosheets as a High-Performance Multifunctional Electrocatalyst

Author

Luo, Liuxuan, Fu, Cehuang, Guo, Yangge, Cai, Xiyang, Luo, Xiashuang, Tan, Zehao, Xue, Rui, Cheng, Xiaojing, Shen, Shuiyun, and Zhang, Junliang

Abstract

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. Accordingly, in this work, sub-5 nm and monodispersed nanodots (NDs) with the special nanostructure of an ultrafine Cu1Au1core and a 2–3-atomic-layer Cu1Pd3shell are synthesized by a facile solvothermal method, which are further evenly and firmly anchored onto 3D porous N-doped graphene nanosheets (NGS) via a simple annealing (A) process. The as-obtained Cu1Au1@Cu1Pd3NDs/NGS-A exhibits exceptional electrocatalytic activity and noble-metal utilization toward the alkaline oxygen reduction, methanol oxidation, and ethanol oxidation reactions, showing dozens-fold enhancements compared with commercial Pd/C and Pt/C. Besides, it also has excellent long-term electrochemical stability and electrocatalytic durability. Advanced and comprehensive experimental and theoretical analyses unveil the synthetic mechanism of the special core@shell nanostructure and further reveal the origins of the significantly enhanced electrocatalytic performance: (1) the prominent structural properties of NGS, (2) the ultrasmall and monodispersed size as well as the highly uniform morphology of the NDs-A, (3) the special Cu–Au–Pd alloy nanostructure with an ultrafine core and a subnanometer shell, and (4) the strong metal–support interaction. This work not only develops a facile method for fabricating the special metal-based ultrafine-core@ultrathin-shell nanostructure but also proposes an effective and practical design paradigm of comprehensively and rationally considering both supports and metal-based nanomaterials for realizing high-performance multifunctional electrocatalysts, which can be further expanded to other supports and metal-based nanomaterials for other energy-conversion or environmental (electro)catalytic applications.

Published
2023
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34. Ultrafine Core@Shell Cu 1 Au 1 @Cu 1 Pd 3 Nanodots Synergized with 3D Porous N-Doped Graphene Nanosheets as a High-Performance Multifunctional Electrocatalyst.

Author

Luo L, Fu C, Guo Y, Cai X, Luo X, Tan Z, Xue R, Cheng X, Shen S, and Zhang J

Abstract

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. Accordingly, in this work, sub-5 nm and monodispersed nanodots (NDs) with the special nanostructure of an ultrafine Cu 1 Au 1 core and a 2-3-atomic-layer Cu 1 Pd 3 shell are synthesized by a facile solvothermal method, which are further evenly and firmly anchored onto 3D porous N-doped graphene nanosheets (NGS) via a simple annealing (A) process. The as-obtained Cu 1 Au 1 @Cu 1 Pd 3 NDs/NGS-A exhibits exceptional electrocatalytic activity and noble-metal utilization toward the alkaline oxygen reduction, methanol oxidation, and ethanol oxidation reactions, showing dozens-fold enhancements compared with commercial Pd/C and Pt/C. Besides, it also has excellent long-term electrochemical stability and electrocatalytic durability. Advanced and comprehensive experimental and theoretical analyses unveil the synthetic mechanism of the special core@shell nanostructure and further reveal the origins of the significantly enhanced electrocatalytic performance: (1) the prominent structural properties of NGS, (2) the ultrasmall and monodispersed size as well as the highly uniform morphology of the NDs-A, (3) the special Cu-Au-Pd alloy nanostructure with an ultrafine core and a subnanometer shell, and (4) the strong metal-support interaction. This work not only develops a facile method for fabricating the special metal-based ultrafine-core@ultrathin-shell nanostructure but also proposes an effective and practical design paradigm of comprehensively and rationally considering both supports and metal-based nanomaterials for realizing high-performance multifunctional electrocatalysts, which can be further expanded to other supports and metal-based nanomaterials for other energy-conversion or environmental (electro)catalytic applications.

Published
2023
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