SGER - Probing Oxygen Reduction Reaction Kinetics Using Heterostructured Thin-Film Microelectrodes

SGER - 使用异质结构薄膜微电极探测氧还原反应动力学

• 批准号: 0844526
• 负责人: Yang Shao-Horn
• 金额: $ 8.8万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0844526&HistoricalAwards=false
• 关键词: SGER; Probing; Oxygen; Reduction; Reaction

CBET-0844526Shao-HornThis objective of this research is to conduct a study of oxygen reduction kinetics to improve our fundamental understanding of oxygen reduction on perovskites, including the relationship of kinetics to surface-specific structure and composition, and exploit this understanding to enhance and stabilize oxide surface electrocatalytic activity. In this project, we focus on our efforts in probing oxygen reduction kinetics by correlating oxygen surface exchange of (La, Sr)x(Mn, Fe, Ni, Cu)yOz perovskite microelectrodes to the bond strength of transition metal and oxygen, where our research is centered around two hypothesis: (1) the surface exchange rate is influenced largely by the electronic structure of oxides rather than oxygen vacancy in the structure; and (2) interface between perovskite ABO3 and A2BO4 type oxides, where such interfaces may enhance oxygen surface exchange as shown by Kawada's recent work. These hypotheses will be examined using the following concepts: (i) for a given transition metal valence state, going from Mn to Cu, the surface exchange rate would be enhanced as the transition metal and oxygen bond strength is reduced; (ii) compositional changes at the ABO3 and A2BO4 oxide interfaces can modify bond strength of transition metal and oxygen as oxygen vacancy may decrease the ionic activity of metal and oxygen bonds and thus lower the bond strength, which might be exploited to enhance oxygen surface exchange rates. The proposed research employs model thin-film microelectrodes to fabricate well-defined systems that allow fundamental investigation of oxygen reduction reaction rate-limiting steps on mixed ionic and electronic conducting perovskite electrocatalysts, and discover the fundamental principles that governs oxygen surface exchange rate. The information would allow researchers to create materials with fast oxygen surface exchange guided by the fundamental principles, and design electrode microstructures at the nanometer-scale for efficient oxygen reduction at intermediate temperatures. The proposed research efforts will generate broad intellectual properties significant to electrochemical energy technologies and create knowledge of interest to the field of catalysis at large. The proposed integrated research and education activities train future energy leaders with interdisciplinary knowledge in electrochemical energy conversion and materials. The outreach program will teach high school teachers and students about energy basics, and will serve to engage K-12 to support energy research and conserve energy through workshop, classroom curriculum development and Service Learning projects.

CBET-0844526 Shao-Horseman本研究的目的是进行氧还原动力学研究，以提高我们对钙钛矿上氧还原的基本理解，包括动力学与表面特定结构和组成的关系，并利用这种理解来增强和稳定氧化物表面电催化活性。 在本计画中，我们致力于探讨氧还原动力学，并将氧表面交换与（La，Sr）x（Mn，Fe，Ni，Cu）yOz钙钛矿微电极对过渡金属与氧的键合强度的影响，我们的研究围绕两个假设展开：（1）表面交换速率主要受氧化物电子结构的影响，而不是结构中氧空位的影响;和（2）钙钛矿ABO 3和A2 BO 4型氧化物之间的界面，如Kawada最近的工作所示，这种界面可以增强氧表面交换。（i）对于给定的过渡金属价态，从Mn到Cu，表面交换速率将随着过渡金属和氧键强度的降低而增强;（二）ABO 3和A2 BO 4氧化物界面处的组成变化可以改变过渡金属和氧的键强度，因为氧空位可以降低金属和氧的离子活性键，从而降低键强度，这可能被用来提高氧表面交换速率。拟议的研究采用模型薄膜微电极来制造定义明确的系统，可以对混合离子和电子导电钙钛矿电催化剂上的氧还原反应限速步骤进行基础研究，并发现控制氧表面交换速率的基本原理。这些信息将使研究人员能够在基本原理的指导下创建具有快速氧表面交换的材料，并在纳米尺度上设计电极微结构，以便在中等温度下有效地还原氧。拟议的研究工作将产生对电化学能源技术具有重要意义的广泛知识产权，并创造对整个催化领域感兴趣的知识。拟议的综合研究和教育活动培养未来的能源领导者，掌握电化学能量转换和材料方面的跨学科知识。该推广计划将向高中教师和学生传授能源基础知识，并将通过研讨会，课堂课程开发和服务学习项目，让K-12支持能源研究和节约能源。