Platinum was electrodeposited onto a polyaniline-modified carbon fiberelectrode by the cyclic voltammetric method in sulfuric acid, which may enable an increase in thelevel of platinum utilization currently achieved i...Platinum was electrodeposited onto a polyaniline-modified carbon fiberelectrode by the cyclic voltammetric method in sulfuric acid, which may enable an increase in thelevel of platinum utilization currently achieved in electrocatalytic systems. This electrodepreparation consists of a two-step procedure: first electropolymerization of aniline onto carbonfiber and then electrodeposition of platinum. The catalytic activity of theplatinum-polyanihne-modified carbon fiber electrode (Pt/PAni/C) was compared with that of a barecarbon fiber electrode (Pt/C) by the oxidation of methanol. The maximum oxidation current ofmethanol on Pt/PAni/C is 50.7 mA centre dot cm^(-2), which is 6.7 times higher than 7.6 mA centredot cm^(-2) on the Pt/C. Scanning electron microscopy was used to investigate the dispersion of theplatinum particles of about 0.4 um.展开更多
This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mas...This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mass transport limitations and ionomer-induced catalyst poisoning.The composite architecture strategically positions Pt/V layer with lower ionomer-to-carbon ratio(I/C=0.6)near the proton exchange membrane to maximize surface Pt accessibility and oxygen transport efficiency,whereas Pt/KB layer(I/C=0.9)adjacent to the gas diffusion layer leverages its porous structure to shield Pt from sulfonate group poisoning and enhance proton conduction under low-humidity conditions.This synergistic carbon support engineering achieves a balance between reactant accessibility and catalyst utilization,as demonstrated by improved power density,reduced transport resistance,and higher Pt utilization under dry conditions.These findings establish a new paradigm for low-Pt CCL design through rational carbon support hybridization and ionomer gradient engineering,offering a scalable solution for high-performance PEMFCs in energy-critical applications.展开更多
Plasma sputtering deposition techniques are good candidates for the fabrication of electrodes used for direct methanol fuel cells （DMFCs）. A house-made plasma sputtering system was used to deposit platinum of 0.1 mg...Plasma sputtering deposition techniques are good candidates for the fabrication of electrodes used for direct methanol fuel cells （DMFCs）. A house-made plasma sputtering system was used to deposit platinum of 0.1 mg/cm^2 onto un-catalyzed gas diffusion layers （GDLs） to form a Pt catalyzed cathode at different radio frequency （RF） powers and sputtering-gas pressures. The sputtered cathodes were assembled in custom-made membrane electrode assemblies （MEAs） with a commercial anode and tested for the electrical performance of the single cell. A custommade MEA with a sputtering prepared cathode was compared with that of a reference membrane electrode assembly made of commercial JM （Johnson Mattey） catalysts （Pt loading per electrode of 0.5 mg/cm^2） under passive methanol supply, ambient temperature and air-breathing conditions. The results showed that the cathode prepared at an input power of 110 W and sputtering-gas pressure of 5.3 Pa exhibited the best cell performance and highest Pt utilization efficiency, which was due to the miniaturization of the Pt particles and formation of the porous catalyst layer. Although the single cell performance of the commercial cathode was better than all the sputtering fabricated cathodes, the Pt utilization efficiency of all the sputtered cathodes was higher than that of the commercial cathode.展开更多
文摘Platinum was electrodeposited onto a polyaniline-modified carbon fiberelectrode by the cyclic voltammetric method in sulfuric acid, which may enable an increase in thelevel of platinum utilization currently achieved in electrocatalytic systems. This electrodepreparation consists of a two-step procedure: first electropolymerization of aniline onto carbonfiber and then electrodeposition of platinum. The catalytic activity of theplatinum-polyanihne-modified carbon fiber electrode (Pt/PAni/C) was compared with that of a barecarbon fiber electrode (Pt/C) by the oxidation of methanol. The maximum oxidation current ofmethanol on Pt/PAni/C is 50.7 mA centre dot cm^(-2), which is 6.7 times higher than 7.6 mA centredot cm^(-2) on the Pt/C. Scanning electron microscopy was used to investigate the dispersion of theplatinum particles of about 0.4 um.
基金financially supported by National Natural Science Foundation of China(22202124 and UA22A20429)Shanxi Scholarship Council of China(2023-008 and 2023-009)+4 种基金Shanxi Outstanding Project Selection and Support Program for Overseas Scientific and Technological Activities(20230002)Science and Technology Innovation Teams of Shanxi Province(202304051001023)the Key Research and Development Program of Shanxi Province(No.202302060301009)Qingdao New Energy Shandong Laboratory Open Project(QNESL OP)Shandong Provincial Natural Science Foundation(Nos.ZR2024QB175 and ZR2023LFG005).
文摘This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mass transport limitations and ionomer-induced catalyst poisoning.The composite architecture strategically positions Pt/V layer with lower ionomer-to-carbon ratio(I/C=0.6)near the proton exchange membrane to maximize surface Pt accessibility and oxygen transport efficiency,whereas Pt/KB layer(I/C=0.9)adjacent to the gas diffusion layer leverages its porous structure to shield Pt from sulfonate group poisoning and enhance proton conduction under low-humidity conditions.This synergistic carbon support engineering achieves a balance between reactant accessibility and catalyst utilization,as demonstrated by improved power density,reduced transport resistance,and higher Pt utilization under dry conditions.These findings establish a new paradigm for low-Pt CCL design through rational carbon support hybridization and ionomer gradient engineering,offering a scalable solution for high-performance PEMFCs in energy-critical applications.
基金supported by National Natural Science Foundation of China (No. 10975162)the Principal Foundation of Institute of Plasma PhysicsChinese Academy of Sciences (No. 095GZ1156Y)
文摘Plasma sputtering deposition techniques are good candidates for the fabrication of electrodes used for direct methanol fuel cells （DMFCs）. A house-made plasma sputtering system was used to deposit platinum of 0.1 mg/cm^2 onto un-catalyzed gas diffusion layers （GDLs） to form a Pt catalyzed cathode at different radio frequency （RF） powers and sputtering-gas pressures. The sputtered cathodes were assembled in custom-made membrane electrode assemblies （MEAs） with a commercial anode and tested for the electrical performance of the single cell. A custommade MEA with a sputtering prepared cathode was compared with that of a reference membrane electrode assembly made of commercial JM （Johnson Mattey） catalysts （Pt loading per electrode of 0.5 mg/cm^2） under passive methanol supply, ambient temperature and air-breathing conditions. The results showed that the cathode prepared at an input power of 110 W and sputtering-gas pressure of 5.3 Pa exhibited the best cell performance and highest Pt utilization efficiency, which was due to the miniaturization of the Pt particles and formation of the porous catalyst layer. Although the single cell performance of the commercial cathode was better than all the sputtering fabricated cathodes, the Pt utilization efficiency of all the sputtered cathodes was higher than that of the commercial cathode.
