First-principles studies of heterogeneous electrochemistry: Electrochemical oxidation reactions over solid oxide fuel cell (SOFC) metal/electrolyte anodes

非均相电化学第一性原理研究：固体氧化物燃料电池（SOFC）金属/电解质阳极上的电化学氧化反应

• 批准号: 0756255
• 负责人: Suljo Linic
• 金额: $ 30万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 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: 2008-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0756255&HistoricalAwards=false
• 关键词: First; principles; studies; heterogeneous; electrochemistry

CBET-0756255LinicSolid oxide fuel cells (SOFCs) are devices that convert chemical energy of combustible fuels into electricity. Important components of solid oxide fuel cells (SOFC) are electrodes (anode and cathode) which activate electrochemical catalytic reactions. Even though, SOFCs are very promising devices, it is astonishing how little is known about the underlying mechanisms of electrochemical reactions that govern the performance of the SOFC electrodes. For example, even for a conceptually very simple H2-oxidation reaction (H2 + O2- = H2O + 2e-) at the SOFC anode, there exist a large number of mutually conflicting elementary step mechanisms that have been proposed based on various experiments. Recent review papers in the field as well as the reports of various scientific advisory committees have emphasized the need for a better molecular level understanding of electrochemical reactions at interfaces of solid electrodes and solid electrolytes. This project will employ quantum Density Functional Theory (DFT) calculations to study elementary step mechanisms of electro-catalytic oxidation reactions over solid oxide fuel cell (SOFC) anodes. We will employ realistic model systems that account for the presence of the metal/electrolyte interface. Potential bias and electric field effects will be incorporated in our first principles calculations. While we focus on SOFC anodes, the proposed methodology is universal and it can be easily employed to address other electro-catalytic systems where solid-state electrochemistry plays a role, such as solid-state sensors, microelectronic devices, solid-state batteries, and many others. We note that the methodology outlined in this proposal has not been utilized previously to study solid-state electrochemistry.The central objective is to aid the development of predictive molecular theories aimed towards the discovery of novel SOFC material. To accomplish these objectives, we have identified four major goals: (1) we will develop a very general methodology that will allow us to study heterogeneous electro-catalytic reaction from first principles, (2) we will asses the thermodynamic feasibility of multiple elementary step mechanisms that have been proposed based on the previous experimental studies of SOFC anodes, (3) we will investigate the kinetics of the various proposed mechanisms by integrating the elementary step information into micro-kinetic models, (4) we will integrate the approach in our educational activities via multiple outreach activities and a new course development.The focus is on the theoretical studies since the solid-state electrochemical reactions are difficult to probe experimentally. The difficulties stem from: (i) an inherent experimental inaccessibility of the catalytically important metal/electrolyte interface sites, (ii) high electric fields, (iii) high potential bias, and (iii) high temperatures at which these reactions take place. The proposed theoretical framework will address these issues. We have already performed significant preliminary work demonstrating the usefulness of the proposed approach.Our central educational objective is to promote molecular approach to energy related science and technology. The educational objectives will be addressed via multiple outreach activities and the integration of the material into the curriculum. For example our group will participate in the Detroit Area Pre-College Engineering Program (DAPCEP) which offers free engineering classes to students in grades 7 and 8 from the Detroit area and the NASA Summer HighSchool Appreciation Program (SHARP) which aims to introduce high school students (grade 10 and 11) to active scientific research.The concepts proposed in this research project will also be integrated into the curriculum by introducing a cluster of courses related to energy and sustainability. This will be taught by a number of faculty members, including the PI, in the department. Furthermore, graduate students who are directly involved in the research program will be exposed to a comprehensive set of theoretical and experimental tools that will allow them to tackle most of the relevant electro-catalysis issues. In addition, we will design an educational module that will be annually presented to large groups of high school students that visit the U of Michigan during summer months. In our laboratory, we also have a three months long research internship that we offer to a promising high school student.

CBET-0756255linicsolid氧化物燃料电池（SOFC）是将可燃燃料的化学能转化为电能的设备。固体氧化物燃料电池（SOFC）的重要成分是激活电化学催化反应的电极（阳极和阴极）。尽管SOFC是非常有前途的设备，但对于控制SOFC电极性能的电化学反应的基本机制知之甚少。例如，即使在概念上非常简单的H2氧化反应（H2 + O2- = H2O + 2E-），也存在许多基于各种实验提出的相互冲突的基本步骤机制。该领域的最新审查论文以及各种科学咨询委员会的报告强调了在固体电极和固体电解质界面上对电化学反应的更好分子水平的必要性。该项目将采用量子密度功能理论（DFT）计算来研究固体氧化物燃料电池（SOFC）阳极上电催化氧化反应的基本步骤机制。我们将采用逼真的模型系统来说明金属/电解质界面的存在。潜在的偏差和电场效应将纳入我们的第一原理计算中。虽然我们专注于SOFC阳极，但提出的方法是通用的，并且可以轻松地用于解决其他电催化系统，在这些系统中，固态电化学起着作用，例如固态传感器，微电子设备，固态电池等。我们注意到，该提案中概述的方法论先前尚未用于研究固态电化学。核心目的是帮助发展旨在发现新型SOFC材料的预测分子理论。为了实现这些目标，我们已经确定了四个主要目标：（1）我们将开发一种非常通用的方法，使我们能够从第一原理研究异质的电催化反应，（2）我们将根据先前提出的基于SOFC ANODES的元素研究提出的多个基本步骤机制的热力学可行性（3），我们将研究Kinet andics（3），我们将提出了多个基本步骤机制的热力学可行性。 （4）我们将通过多个外展活动和新的课程开发将方法整合到我们的教育活动中。重点是理论研究，因为固态电化学反应很难实验。困难源于：（i）催化重要的金属/电解质界面位点，（ii）高电场，（iii）高电位偏置以及（iii）这些反应发生的高温。提出的理论框架将解决这些问题。我们已经进行了重要的初步工作，证明了拟议方法的有用性。我们的中央教育目标是促进与能量相关的科学和技术的分子方法。教育目标将通过多种外展活动以及将材料整合到课程中来解决。例如，我们的小组将参加底特律领域的预科工程课程（DAPCEP），该计划为从底特律地区的7年级和8年级的学生提供免费的工程课程，以及NASA夏季夏季高中欣赏计划（SHARP），旨在介绍高中学生（10年级和11年级），以介绍这项概念的概念。和可持续性。这将由部门在内的许多教师（包括PI）教授。此外，直接参与研究计划的研究生将接触到一系列全面的理论和实验工具，这些工具将使他们能够解决大多数相关的电催化问题。此外，我们将设计一个教育模块，该模块每年将向夏季访问密歇根州U的大型高中学生展示。在我们的实验室中，我们还为有前途的高中生提供了三个月的研究实习。