Corrosion of Nanoscale Alloy Electrodes

纳米合金电极的腐蚀

• 批准号: 0855969
• 负责人: Karl Sieradzki
• 金额: $ 50万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-15 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0855969&HistoricalAwards=false
• 关键词: Corrosion; Nanoscale; Alloy; Electrodes

TECHNICAL SUMMARY:This research project examines alloy corrosion processes in nanoscale structures. The program involves a combined experimental and theoretical approach focused on developing broadly applicable thermodynamic models of dealloying corrosion. This problem is extraordinarily rich in that there are two intrinsic length scales that must be considered. One length scale is set by the alloy composition and the other is set by the physical dimensions of the sample. The richness of the problem derives from the interaction of these length scales, which leads to entirely new corrosion phenomena. Corrosion of such structures is important at monolayer levels and occurs at compositions which are not vulnerable to attack in corresponding larger macroscopic scale samples. Thus conventional approaches for characterizing dealloying corrosion are not applicable at the nanoscale. In order to perform this work we use a new technique for developing reproducible alloy nanoelectrodes in the size range of 3 ? 10 nm and employ a variety of characterization techniques including underpotential deposition for assaying surface compositions, electrochemical scanning tunneling microscopy and high resolution analytical transmission electron microscopy. The combination of experimental data generated on well characterized nanostructures together with our thermodynamic modeling will provide a general fundamental framework for understanding these important nanoscale corrosion processes. The science evolving from this research will impact diverse applications in nanotechnology.NON-TECHNICAL SUMMARY:This research examines corrosion of nanoscale structures such as those used as catalysts in fuel cells, nanoparticle based bio-assays, bio-sensing and environmental monitoring for security and surveillance. In the case of fuel cells for transportable power the stability of metal alloy catalyst particles to corrosion is the key problem and to date has limited this technology to widespread application. This program is evolving new experimental data and modeling that will provide engineering guidelines for the design of nanoscale structures that are stable to corrosion. In order to accomplish these goals students are trained to develop expertise in order to integrate knowledge in the disciplines of electrochemistry and materials science. Today there is a dearth of graduate students trained in the U.S. in this manner. Part of this problem stems from the perception students have that corrosion science is an old developed field and is separated from the current hot areas which include fields such as renewable energy and ?bio-nano?. This research program opens a new arena in corrosion science which should help to get more high quality students interested in corrosion. In support of this, we are developing new courses in materials electrochemistry which specifically focuses on the corrosion and electrochemical behavior of nanoelectrodes. This will be taught at the senior undergraduate/beginning graduate level and is aimed specifically at exciting student interest in this field. Both graduate and undergraduate students are involved in this research program. In addition to active involvement with the NSF funded Minority Graduate Education @ Mountain State Alliance (MGE@MSA) program, the PI is getting individuals from underrepresented groups involved in this research program.

技术概要：本研究项目探讨纳米结构中的合金腐蚀过程。该计划涉及实验和理论相结合的方法，重点是开发广泛适用的脱合金腐蚀热力学模型。这个问题是非常丰富的，因为有两个内在的长度尺度，必须考虑。一个长度标度由合金成分设定，另一个由样品的物理尺寸设定。这个问题的丰富性来自于这些长度尺度的相互作用，这导致了全新的腐蚀现象。这种结构的腐蚀在单层水平上是重要的，并且发生在相应的较大宏观尺度样品中不易受到攻击的组合物上。因此，表征脱合金腐蚀的常规方法在纳米级上不适用。为了执行这项工作，我们使用一种新的技术开发可重复的合金纳米电极的尺寸范围为3？10 nm，并采用各种表征技术，包括用于分析表面成分的欠电位沉积，电化学扫描隧道显微镜和高分辨率分析透射电子显微镜。结合我们的热力学模型以及表征纳米结构上产生的实验数据，将为理解这些重要的纳米级腐蚀过程提供一个通用的基本框架。从这项研究中发展出来的科学将影响纳米技术的各种应用。非技术性总结：这项研究探讨了纳米结构的腐蚀，例如用于燃料电池的催化剂，基于纳米颗粒的生物测定，生物传感和安全和监视的环境监测。在用于可运输功率的燃料电池的情况下，金属合金催化剂颗粒的抗腐蚀稳定性是关键问题，并且迄今为止限制了该技术的广泛应用。该计划正在开发新的实验数据和建模，为设计耐腐蚀的纳米结构提供工程指导。为了实现这些目标，学生接受培训，以发展专业知识，以整合电化学和材料科学学科的知识。今天，在美国，以这种方式培养的研究生非常缺乏。这个问题的一部分源于学生的看法，腐蚀科学是一个古老的发达领域，是从目前的热点领域，其中包括可再生能源和？生物纳米？本研究项目为腐蚀科学开辟了一个新的竞技场，有助于培养更多对腐蚀感兴趣的高素质学生。为了支持这一点，我们正在开发新的材料电化学课程，特别关注纳米电极的腐蚀和电化学行为。这将在高年级本科生/研究生开始水平教授，并专门针对激发学生对这一领域的兴趣。研究生和本科生都参与了这项研究计划。除了积极参与NSF资助的少数民族研究生教育@山区国家联盟（MGE@MSA）计划外，PI还从参与这项研究计划的代表性不足的群体中获得个人。