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
The development of clean and sustainable energy sources is vital to address energy and environmental challenges.The generation of green hydrogen using efficient hydrogen evolution electrocatalysts is one of the promis...The development of clean and sustainable energy sources is vital to address energy and environmental challenges.The generation of green hydrogen using efficient hydrogen evolution electrocatalysts is one of the promising approaches towards this goal.Among various HER electrocatalysts studied to date,Pt remains one of the most active catalysts which shows superior HER performance.However,its high cost due to scarcity impedes its potential large-scale commercialization at low cost.Therefore,increasing the Pt utilization efficiency without hampering its catalytic activity is the prime goal.In this review we will discuss recent progress made in increasing Pt utilization efficiency.The review starts by summarizing the basic mechanism and fundamentals of the HER.Then,in the next three sections recent progress made towards increasing Pt utilization efficiency by forming Pt alloys,heterostructures and single-atom Pt catalysts is discussed in detail.In the last section we discuss the role of pH and supporting cations in altering the HER rate on the surface of Pt catalysts.This research topic has not been much discussed in reviews and various mechanisms have been proposed for its basis,which are also presented.We hope that this review will help researchers better understand the recent advances made in improving Pt utilization efficiency.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
It is an effective strategy to enhance platinum(Pt)utilization and lower the catalyst cost by loading Pt on a self-supported electrode.In this work,we employ a molybdenum(Mo)mesh both as the source of Mo and the self-...It is an effective strategy to enhance platinum(Pt)utilization and lower the catalyst cost by loading Pt on a self-supported electrode.In this work,we employ a molybdenum(Mo)mesh both as the source of Mo and the self-supported electrode.Through a successful combination of the spray and calcination methods,Pt is efficiently loaded onto the self-supported molybdenum dioxide(MoO_(2))electrode,achieving a Pt loading content of only∼0.67 wt%.Simultaneously,three-dimensional(3D)MoO_(2)exhibits a structure comprised of nanosheets,each possessing perforations.As expected,the prepared electrocatalyst demonstrates exceptional performance,manifesting an overpotential of 26.8 mV at−10 mA cm^(-2),a Tafel slope of 59.2 mV dec^(-1),and a noteworthy durability of over 240 hours.Both experimental studies and theoretical calculations affirm that the catalyst’s outstanding performance stems from the strong interaction between Pt and MoO_(2),the distinctive structure of MoO_(2)with perforated nanosheets,and the self-supporting characteristics of the electrode.This work introduces an efficient method for constructing self-supporting heterojunctions,thereby advancing the development of electrocatalytic hydrogen evolution.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support from NSERC Canada,CFI Canada,Ministry of Colleges and Universities,Ontario,Mitacs Canada,and the University of Waterloo.
文摘The development of clean and sustainable energy sources is vital to address energy and environmental challenges.The generation of green hydrogen using efficient hydrogen evolution electrocatalysts is one of the promising approaches towards this goal.Among various HER electrocatalysts studied to date,Pt remains one of the most active catalysts which shows superior HER performance.However,its high cost due to scarcity impedes its potential large-scale commercialization at low cost.Therefore,increasing the Pt utilization efficiency without hampering its catalytic activity is the prime goal.In this review we will discuss recent progress made in increasing Pt utilization efficiency.The review starts by summarizing the basic mechanism and fundamentals of the HER.Then,in the next three sections recent progress made towards increasing Pt utilization efficiency by forming Pt alloys,heterostructures and single-atom Pt catalysts is discussed in detail.In the last section we discuss the role of pH and supporting cations in altering the HER rate on the surface of Pt catalysts.This research topic has not been much discussed in reviews and various mechanisms have been proposed for its basis,which are also presented.We hope that this review will help researchers better understand the recent advances made in improving Pt utilization efficiency.
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.
基金supported by the National Natural Science Foundation of China(No.52374395)the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.22HASTIT008,24HASTIT006)+2 种基金the Natural Science Foundations of Henan Province(No.222300420502,242300420045)the Programs for Science and Technology Development of Henan Province(No.242102240066)the Key Scientific Research Projects of University in Henan Province(No.23B430002).
文摘It is an effective strategy to enhance platinum(Pt)utilization and lower the catalyst cost by loading Pt on a self-supported electrode.In this work,we employ a molybdenum(Mo)mesh both as the source of Mo and the self-supported electrode.Through a successful combination of the spray and calcination methods,Pt is efficiently loaded onto the self-supported molybdenum dioxide(MoO_(2))electrode,achieving a Pt loading content of only∼0.67 wt%.Simultaneously,three-dimensional(3D)MoO_(2)exhibits a structure comprised of nanosheets,each possessing perforations.As expected,the prepared electrocatalyst demonstrates exceptional performance,manifesting an overpotential of 26.8 mV at−10 mA cm^(-2),a Tafel slope of 59.2 mV dec^(-1),and a noteworthy durability of over 240 hours.Both experimental studies and theoretical calculations affirm that the catalyst’s outstanding performance stems from the strong interaction between Pt and MoO_(2),the distinctive structure of MoO_(2)with perforated nanosheets,and the self-supporting characteristics of the electrode.This work introduces an efficient method for constructing self-supporting heterojunctions,thereby advancing the development of electrocatalytic hydrogen evolution.
