摘要
铂(Pt)是质子交换膜燃料电池(PEMFCs)阳极氢氧化反应(HOR)中最先进的电催化剂.然而,Pt催化剂对CO(工业低成本氢燃料中的杂质)极度敏感从而中毒,这会引起器件性能的急剧衰退,导致器件运行成本高.因此,提高Pt催化剂的CO耐受性对PEMFCs的商业化推广至关重要.在此,我们设计合成了一种独特的PtNiW@WO_(x)核壳纳米线来提高Pt基催化剂对CO的耐受能力.机理研究表明,表面无定形的WO_(x)壳层可以作为分子围栏,在动力学上阻碍CO扩散到达Pt位点.在热力学上,Ni和W元素合金化产生的电子效应可以使Pt的d带中心降低,减弱CO在Pt位点上的化学吸附.此外,亲氧W元素可以加速水的解离,提供更多OH活性物种,促进CO的氧化脱附.因此,在1000ppm CO/H_(2)条件下,所设计的PtNiW@WO_(x)核壳纳米线催化剂表现出优异的HOR抗CO中毒性能,在4000 s后仍能保持超过90%的HOR电流密度,超过了原始的PtNi纳米线和目前报道的绝大多数Pt基催化剂.
Platinum(Pt)is the state-of-the-art electro-catalyst for anodic hydrogen oxidation reaction(HOR)in proton exchange membrane fuel cells(PEMFCs).However,a critical drawback of PEMFCs is the extreme sensitivity of Pt catalyst to CO(impurity in industrial hydrogen),which markedly damages the device’s performance.Therefore,en-hancing the CO-tolerant performance of Pt catalysts is crucial for the commercialization of PEMFCs.Herein,we constructed PtNiW@amorphous WO_(x) core-shell nanowires to improve the CO-tolerance of Pt.Mechanistically,it is demonstrated that the surface amorphous WO_(x) shell can kinetically hinder the accessibility of CO over Pt sites by acting as a selective mole-cular-sieving layer.Besides,thermodynamically,the electronic effect from the alloying of Ni and W elements could weaken the CO adsorption on Pt sites by downshifting the d-band center.In addition,the oxyphilic W elements can accelerate the dissociation of water to provide more OH species,pro-moting the oxidation of CO.As a consequence,the as-de-signed PtNiW@WO_(x) NWs can maintain over 90%HOR current density after 4000 s in 1000 ppm CO/H_(2),exceeding most of the Pt-based catalysts reported ever.
作者
刘巍
杨馥榕
孙土来
黄晨明
赖文川
杜佳峰
叶进裕
曾昱嘉
高磊
黄宏文
Wei Liu;Furong Yang;Tulai Sun;Chenming Huang;Wenchuan Lai;Jiafeng Du;Jinyu Ye;Yujia Zeng;Lei Gao;Hongwen Huang(College of Materials Science and Engineering,Hunan University,Changsha 410082,China;Center for Electron Microscopy,State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology and College of Chemical Engineering,Zhejiang University of Technology,Hangzhou 310014,China;College of Chemistry and Materials Science,Nanjing Normal University,Nanjing 210023,China;State Key Laboratory for Physical Chemistry of Solid Surfaces,Collaborative Innovation Center of Chemistry for Energy Materials,Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China;Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China;Shenzhen Research Institute of Hunan University,Shenzhen 518055,China)
基金
supported by the National Natural Science Foundation of China (22322902,U22A20396,22102052,22309050,and 22211540385)
the National Key Research and Development Program of China (2021YFA1502000)
the Science and Technology Innovation Program of Hunan Province (2021RC3065)
Jiebang Guashuai Project of Changsha City (kq2301009)
Shenzhen Science and Technology Program (JCYJ20210324120800002,JCYJ20220818100012025,and JCYJ20230807122007015)
China Postdoctoral Science Foundation (2023T160205)。
