To address the problem of fuel starvation in fuel-cell electric vehicles,which causes cell voltage reversal and results in cell failure when repeated continuously,we developed a reversal-tolerant anode(RTA) to promote...To address the problem of fuel starvation in fuel-cell electric vehicles,which causes cell voltage reversal and results in cell failure when repeated continuously,we developed a reversal-tolerant anode(RTA) to promote water oxidation in preference to carbon corrosion.Graphitized carbon-supported Ir-Ru alloys with different compositions are employed as RTA catalysts in an acidic polyol solution and are shown to exhibit composition-dependent average crystallite sizes of <5.33 nm.The adopted approach allows the generation of relatively well-dispersed Ir-Ru alloy nanoparticles on the carbon support without severe agglomeration.The activity of IrRu_(2)/C for the hydrogen oxidation reaction is 1.10 times that of the stateof-the-art Pt/C catalyst.Cell reversal testing by simulation of fuel starvation reveals that the durability of IrRu_(2)/C(~7 h) significantly exceeds that of the conventional Pt/C catalyst(~10 min) and is the highest value reported so far.Thus,the developed Ir-Ru alloy catalyst can be used to fabricate practical RTAs and replace Pt catalysts in the anodes of polymer electrolyte membrane fuel cells.展开更多
In this work,the effect of Nafion ionomer content on the structure and catalytic performance of direct CO polymer electrolyte membrane fuel cell(CO-PEMFC)by using Rh-N-C single-atom catalyst as the anode catalyst laye...In this work,the effect of Nafion ionomer content on the structure and catalytic performance of direct CO polymer electrolyte membrane fuel cell(CO-PEMFC)by using Rh-N-C single-atom catalyst as the anode catalyst layers was studied.The ionic plaque and roughness of the anode catalyst layers increase with the increase of Nafion ionomer content.Furthermore,the contact angle measurement results show that the hydrophilicity of the anode catalyst layers also increases with the increase of Nafion ionomer content.However,when the Nafion ionomer content is too low,the binding between microporous layers,catalyst layers and membrane cannot meet the requirement for either electric conductivity or mass transfer.While Nafion ionomer content increased above 30%,the content of water in anode is difficult to control.Therefore,it was found that AN 30(30%Nafion ionomer content of anode)is the best level to effectively extend the three-phase boundary and improve CO-PEMFCs performance.展开更多
Since the commercialization of the fuel cell electric vehicles (FCEVs), the polymer electrolyte membrane fuel cell system has been actively improved as a powertrain for ultimate environment-friendly vehicle. During th...Since the commercialization of the fuel cell electric vehicles (FCEVs), the polymer electrolyte membrane fuel cell system has been actively improved as a powertrain for ultimate environment-friendly vehicle. During the FCEV operation, various transient conditions such as start-up/shut-down and fuel starvation occur irregularly, which deteriorates the durability of the membrane electrode assembly. In particular, when fuel starvation occurs, the carbon support in the anode is oxidized within few minutes, thus the mitigation of this phenomenon is essential for securing the durability. This short review introduces the concept of reversal tolerant anode (RTA), which is a mitigation method using an oxygen evolution catalyst and reviews some previous reports. In addition, new approach for RTA suggested by authors recently, which is the replacement of Pt anode catalyst by multifunctional IrRu alloy catalyst that simultaneously exhibits the activities for the hydrogen oxidation reaction and the oxygen evolution reaction is introduced.展开更多
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea[Grant No.20183010032380]a GIST Research Institute(GRI)grant funded by the GIST in 2020。
文摘To address the problem of fuel starvation in fuel-cell electric vehicles,which causes cell voltage reversal and results in cell failure when repeated continuously,we developed a reversal-tolerant anode(RTA) to promote water oxidation in preference to carbon corrosion.Graphitized carbon-supported Ir-Ru alloys with different compositions are employed as RTA catalysts in an acidic polyol solution and are shown to exhibit composition-dependent average crystallite sizes of <5.33 nm.The adopted approach allows the generation of relatively well-dispersed Ir-Ru alloy nanoparticles on the carbon support without severe agglomeration.The activity of IrRu_(2)/C for the hydrogen oxidation reaction is 1.10 times that of the stateof-the-art Pt/C catalyst.Cell reversal testing by simulation of fuel starvation reveals that the durability of IrRu_(2)/C(~7 h) significantly exceeds that of the conventional Pt/C catalyst(~10 min) and is the highest value reported so far.Thus,the developed Ir-Ru alloy catalyst can be used to fabricate practical RTAs and replace Pt catalysts in the anodes of polymer electrolyte membrane fuel cells.
基金National Natural Science Foundation of China(Nos.21633008,21875243,21673221 and U1601211)Science and Technology Development Program of Jilin Province,China(Nos.20200201001JC,20190201270JC and 20180101030JC).
文摘In this work,the effect of Nafion ionomer content on the structure and catalytic performance of direct CO polymer electrolyte membrane fuel cell(CO-PEMFC)by using Rh-N-C single-atom catalyst as the anode catalyst layers was studied.The ionic plaque and roughness of the anode catalyst layers increase with the increase of Nafion ionomer content.Furthermore,the contact angle measurement results show that the hydrophilicity of the anode catalyst layers also increases with the increase of Nafion ionomer content.However,when the Nafion ionomer content is too low,the binding between microporous layers,catalyst layers and membrane cannot meet the requirement for either electric conductivity or mass transfer.While Nafion ionomer content increased above 30%,the content of water in anode is difficult to control.Therefore,it was found that AN 30(30%Nafion ionomer content of anode)is the best level to effectively extend the three-phase boundary and improve CO-PEMFCs performance.
基金supported by Hyundai Mobis(No. G106280)the Gwangju Institute of Science and Technology in 2019
文摘Since the commercialization of the fuel cell electric vehicles (FCEVs), the polymer electrolyte membrane fuel cell system has been actively improved as a powertrain for ultimate environment-friendly vehicle. During the FCEV operation, various transient conditions such as start-up/shut-down and fuel starvation occur irregularly, which deteriorates the durability of the membrane electrode assembly. In particular, when fuel starvation occurs, the carbon support in the anode is oxidized within few minutes, thus the mitigation of this phenomenon is essential for securing the durability. This short review introduces the concept of reversal tolerant anode (RTA), which is a mitigation method using an oxygen evolution catalyst and reviews some previous reports. In addition, new approach for RTA suggested by authors recently, which is the replacement of Pt anode catalyst by multifunctional IrRu alloy catalyst that simultaneously exhibits the activities for the hydrogen oxidation reaction and the oxygen evolution reaction is introduced.
