The catalyst layers(CLs) electrode is the key component of the membrane electrode assembly(MEA) in proton exchange membrane fuel cells(PEMFCs). Conventional electrodes for PEMFCs are composed of carbon-supported, iono...The catalyst layers(CLs) electrode is the key component of the membrane electrode assembly(MEA) in proton exchange membrane fuel cells(PEMFCs). Conventional electrodes for PEMFCs are composed of carbon-supported, ionomer, and Pt nanoparticles, all immersed together and sprayed with a micron-level thickness of CLs. They have a performance trade-off where increasing the Pt loading leads to higher performance of abundant triple-phase boundary areas but increases the electrode cost. Major challenges must be overcome before realizing its wide commercialization. Literature research revealed that it is impossible to achieve performance and durability targets with only high-performance catalysts, so the controllable design of CLs architecture in MEAs for PEMFCs must now be the top priority to meet industry goals. From this perspective, a 3D ordered electrode circumvents this issue with a support-free architecture and ultrathin thickness while reducing noble metal Pt loadings. Herein, we discuss the motivation in-depth and summarize the necessary CLs structural features for designing ultralow Pt loading electrodes. Critical issues that remain in progress for 3D ordered CLs must be studied and characterized. Furthermore, approaches for 3D ordered CLs architecture electrode development, involving material design, structure optimization, preparation technology, and characterization techniques, are summarized and are expected to be next-generation CLs for PEMFCs. Finally, the review concludes with perspectives on possible research directions of CL architecture to address the significant challenges in the future.展开更多
受量子理论启发,结合数学形态滤波器中的膨胀算子,提出合成量子启发结构元素(Compound quantum-inspired structuring element,CQSE),用于增强故障振动信号中的冲击响应成分。CQSE综合考虑了信号的局部特征和随机性,其高度能够跟随信号...受量子理论启发,结合数学形态滤波器中的膨胀算子,提出合成量子启发结构元素(Compound quantum-inspired structuring element,CQSE),用于增强故障振动信号中的冲击响应成分。CQSE综合考虑了信号的局部特征和随机性,其高度能够跟随信号的变化进行动态调整。首先,建立了量子启发结构元素(Quantum-inspired structuring element,QSE)的基本数学表达式。随后,采用峭度描述冲击响应信号的局部特征,并用于生成QSE在实数空间的单一形式(Single form in real space,SFRS)的高度;采用信号的归一化振动大小描述信号的随机性,并用于计算不同SFRS出现的量子概率。然后,结合量子概率,通过数学期望,对不同的SFRS进行合成,获得应用于膨胀算子的CQSE。最后,将CQSE应用于轴承故障诊断,有效地增强了故障信息。展开更多
基金funded by the Natural Science Foundation of Shandong Province, China (ZR2023MB049)the China Postdoctoral Science Foundation (2020M670483)the Science Foundation of Weifang University (2023BS11)。
文摘The catalyst layers(CLs) electrode is the key component of the membrane electrode assembly(MEA) in proton exchange membrane fuel cells(PEMFCs). Conventional electrodes for PEMFCs are composed of carbon-supported, ionomer, and Pt nanoparticles, all immersed together and sprayed with a micron-level thickness of CLs. They have a performance trade-off where increasing the Pt loading leads to higher performance of abundant triple-phase boundary areas but increases the electrode cost. Major challenges must be overcome before realizing its wide commercialization. Literature research revealed that it is impossible to achieve performance and durability targets with only high-performance catalysts, so the controllable design of CLs architecture in MEAs for PEMFCs must now be the top priority to meet industry goals. From this perspective, a 3D ordered electrode circumvents this issue with a support-free architecture and ultrathin thickness while reducing noble metal Pt loadings. Herein, we discuss the motivation in-depth and summarize the necessary CLs structural features for designing ultralow Pt loading electrodes. Critical issues that remain in progress for 3D ordered CLs must be studied and characterized. Furthermore, approaches for 3D ordered CLs architecture electrode development, involving material design, structure optimization, preparation technology, and characterization techniques, are summarized and are expected to be next-generation CLs for PEMFCs. Finally, the review concludes with perspectives on possible research directions of CL architecture to address the significant challenges in the future.
文摘受量子理论启发,结合数学形态滤波器中的膨胀算子,提出合成量子启发结构元素(Compound quantum-inspired structuring element,CQSE),用于增强故障振动信号中的冲击响应成分。CQSE综合考虑了信号的局部特征和随机性,其高度能够跟随信号的变化进行动态调整。首先,建立了量子启发结构元素(Quantum-inspired structuring element,QSE)的基本数学表达式。随后,采用峭度描述冲击响应信号的局部特征,并用于生成QSE在实数空间的单一形式(Single form in real space,SFRS)的高度;采用信号的归一化振动大小描述信号的随机性,并用于计算不同SFRS出现的量子概率。然后,结合量子概率,通过数学期望,对不同的SFRS进行合成,获得应用于膨胀算子的CQSE。最后,将CQSE应用于轴承故障诊断,有效地增强了故障信息。
