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Eliminating dissolution of platinum-based electrocatalysts at the atomic scale.
Nature Materials ( IF 37.2 ) Pub Date : 2020-07-20 , DOI: 10.1038/s41563-020-0735-3
Pietro P Lopes 1 , Dongguo Li 1 , Haifeng Lv 1 , Chao Wang 2 , Dusan Tripkovic 1, 3 , Yisi Zhu 1 , Roberto Schimmenti 4 , Hideo Daimon 5 , Yijin Kang 1 , Joshua Snyder 6 , Nigel Becknell 1 , Karren L More 7 , Dusan Strmcnik 1 , Nenad M Markovic 1 , Manos Mavrikakis 4 , Vojislav R Stamenkovic 1
Affiliation  

A remaining challenge for the deployment of proton-exchange membrane fuel cells is the limited durability of platinum (Pt) nanoscale materials that operate at high voltages during the cathodic oxygen reduction reaction. In this work, atomic-scale insight into well-defined single-crystalline, thin-film and nanoscale surfaces exposed Pt dissolution trends that governed the design and synthesis of durable materials. A newly defined metric, intrinsic dissolution, is essential to understanding the correlation between the measured Pt loss, surface structure, size and ratio of Pt nanoparticles in a carbon (C) support. It was found that the utilization of a gold (Au) underlayer promotes ordering of Pt surface atoms towards a (111) structure, whereas Au on the surface selectively protects low-coordinated Pt sites. This mitigation strategy was applied towards 3 nm Pt3Au/C nanoparticles and resulted in the elimination of Pt dissolution in the liquid electrolyte, which included a 30-fold durability improvement versus 3 nm Pt/C over an extended potential range up to 1.2 V.



中文翻译:

在原子尺度上消除铂基电催化剂的溶解。

部署质子交换膜燃料电池的另一个挑战是铂(Pt)纳米级材料的耐久性有限,该材料在阴极氧还原反应过程中会在高压下工作。在这项工作中,对定义明确的单晶,薄膜和纳米级表面的原子级洞察力揭示了Pt溶解趋势,该趋势控制着耐用材料的设计和合成。新定义的度量标准(固有溶解度)对于理解测得的碳(C)载体中Pt损失,表面结构,尺寸和Pt纳米颗粒比例之间的相关性至关重要。发现利用金(Au)底层促进了Pt表面原子向(111)结构的有序化,而表面上的Au选择性地保护了低配位的Pt位点。3 Au / C纳米粒子,消除了Pt在液体电解质中的溶解,在高达1.2 V的扩展电位范围内,与3 nm Pt / C相比,耐久性提高了30倍。

更新日期:2020-07-20
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