High performance cathode for polymer electrolyte membrane fuel cell was prepared by depositing Pt nanowires in a carbon matrix coated on a substrate, and using decal transfer method to fabricate the membrane electrode...High performance cathode for polymer electrolyte membrane fuel cell was prepared by depositing Pt nanowires in a carbon matrix coated on a substrate, and using decal transfer method to fabricate the membrane electrode assembly. The effects of carbon and ionomer contents on the electrode micro-structure and fuel cell performance are investigated by physical characterization and single cell testing. The Pt nanowires are gradient distributed across the cathode thickness, and more Pt exists near the membrane. Both the carbon and ionomer contents can affect the Pt nanowires distribution and aggregation. In addition, the carbon loading dominates the transport distance of gas and proton, and the ionomer content affects the triple phase boundaries and porosity in the cathode. The optimal structure of Pt nanowire cathode is obtained at 0.10 mg·cm^-2 carbon loading and 10 wt% ionomer.展开更多
Recently, the synthesis of ultrathin nanostructures has attracted increasing interest because of their unique structure and properties. In this work, we report the synthesis of sub-2.0-nm Ru and composition-tunable Ru...Recently, the synthesis of ultrathin nanostructures has attracted increasing interest because of their unique structure and properties. In this work, we report the synthesis of sub-2.0-nm Ru and composition-tunable RuPt nanowire networks using an environmentally friendly aqueous method. The structures were characterized using transmission electron microscopy (TEM), high-resolution TEM, X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) spectroscopy. Moreover, the combined utilization of sodium n-dodecyl sulfate and potassium fluoride was determined to play a key role in the formation of these ultrathin nanostructures. The electrocatalytic properties of the sub-2.0-nm RuPt nanowire networks were investigated for methanol oxidation in an acidic medium. The nanostructures displayed composition-dependent properties, and compared with commercial Ru50Pt50/C, the as-synthesized Ru56Pt44 ultrathin nanowire network exhibited enhanced stability.展开更多
Ni modification is considered as an efficient strategy for boosting the performance of Pt towards alkaline hydrogen oxidation reaction(HOR),yet its specific role is largely undecoded.Here,ultrathin Pt nanowires(NWs)ar...Ni modification is considered as an efficient strategy for boosting the performance of Pt towards alkaline hydrogen oxidation reaction(HOR),yet its specific role is largely undecoded.Here,ultrathin Pt nanowires(NWs)are selected as models for revealing the significance of Ni modification on HOR by precisely positioning Ni on distinct positions of Pt NWs.Ni solely influences the electronic properties of Pt and thus weakens*H adsorption when it is located in the core of PtNi alloyed NWs,leading to a moderate improvement of alkaline HOR activity.When Ni is distributed in both core and surface of PtNi alloyed NWs,Ni strongly weakens*H adsorption but strengthens*OH adsorption.On the other hand,the electronic properties of Pt are hardly influenced when Ni is deposited on the surface of Pt NWs,on which the strong*H and*OH adsorptions lead to the improved HOR activity.This work reveals the significance of Ni modification on HOR,but also promotes the fundamental researches on catalyst design for fuel cell reactions and beyond.展开更多
The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells.In this paper,accurately controlled growth of nanowires in a carbon matrix is achi...The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells.In this paper,accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading.The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires,as well as their electrochemical performances in a single cell,are investigated.The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires.With increasing reduction temperature,the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40°C.A mechanism of the Pt nanowires growth is proposed.The optimized Pt nanowires electrode exhibits a power density(based on electrochemical active surface area)79%higher than conventional Pt/C one.The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.展开更多
文摘High performance cathode for polymer electrolyte membrane fuel cell was prepared by depositing Pt nanowires in a carbon matrix coated on a substrate, and using decal transfer method to fabricate the membrane electrode assembly. The effects of carbon and ionomer contents on the electrode micro-structure and fuel cell performance are investigated by physical characterization and single cell testing. The Pt nanowires are gradient distributed across the cathode thickness, and more Pt exists near the membrane. Both the carbon and ionomer contents can affect the Pt nanowires distribution and aggregation. In addition, the carbon loading dominates the transport distance of gas and proton, and the ionomer content affects the triple phase boundaries and porosity in the cathode. The optimal structure of Pt nanowire cathode is obtained at 0.10 mg·cm^-2 carbon loading and 10 wt% ionomer.
基金This work was supported by the National Natural Science Foundation of China (Nos. 21361005 and 21571038) and Graduate Innovation Foundation of Guizhou University (No. 2015031). The experimental work was mainly done in National University of Singapore and we also appreciate the useful discussion with Prof. Hua Chun Zeng of the National University of Singapore about this work.
文摘Recently, the synthesis of ultrathin nanostructures has attracted increasing interest because of their unique structure and properties. In this work, we report the synthesis of sub-2.0-nm Ru and composition-tunable RuPt nanowire networks using an environmentally friendly aqueous method. The structures were characterized using transmission electron microscopy (TEM), high-resolution TEM, X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) spectroscopy. Moreover, the combined utilization of sodium n-dodecyl sulfate and potassium fluoride was determined to play a key role in the formation of these ultrathin nanostructures. The electrocatalytic properties of the sub-2.0-nm RuPt nanowire networks were investigated for methanol oxidation in an acidic medium. The nanostructures displayed composition-dependent properties, and compared with commercial Ru50Pt50/C, the as-synthesized Ru56Pt44 ultrathin nanowire network exhibited enhanced stability.
基金supports by the National Key R&D Program of China(No.2020YFB1505802)the Ministry of Science and Technology of China(Nos.2017YFA0208200,and 2016YFA0204100)+2 种基金the National Natural Science Foundation of China(Nos.22025108,22121001 and 51802206)Guangdong Provincial Natural Science Fund for Distinguished Young Scholars(No.2021B1515020081)Start-up Supports from Xiamen University and Guangzhou Key Laboratory of Low Dimensional Materials and Energy Storage Devices(No.20195010002).
文摘Ni modification is considered as an efficient strategy for boosting the performance of Pt towards alkaline hydrogen oxidation reaction(HOR),yet its specific role is largely undecoded.Here,ultrathin Pt nanowires(NWs)are selected as models for revealing the significance of Ni modification on HOR by precisely positioning Ni on distinct positions of Pt NWs.Ni solely influences the electronic properties of Pt and thus weakens*H adsorption when it is located in the core of PtNi alloyed NWs,leading to a moderate improvement of alkaline HOR activity.When Ni is distributed in both core and surface of PtNi alloyed NWs,Ni strongly weakens*H adsorption but strengthens*OH adsorption.On the other hand,the electronic properties of Pt are hardly influenced when Ni is deposited on the surface of Pt NWs,on which the strong*H and*OH adsorptions lead to the improved HOR activity.This work reveals the significance of Ni modification on HOR,but also promotes the fundamental researches on catalyst design for fuel cell reactions and beyond.
基金We gratefully acknowledge the financial supports from the National Natural Science Foundation of China(Grant No.21576164)the European Union’s Horizon 2020 research and innovation program H2020-MSCA-IF-2014(Grant No.658217)Anhui new energy vehicle and intelligent network vehicle industry technology innovation project(Grant No.2018-599)of Anhui development and Reform Commission.
文摘The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells.In this paper,accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading.The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires,as well as their electrochemical performances in a single cell,are investigated.The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires.With increasing reduction temperature,the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40°C.A mechanism of the Pt nanowires growth is proposed.The optimized Pt nanowires electrode exhibits a power density(based on electrochemical active surface area)79%higher than conventional Pt/C one.The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.