Binary Palladium-Based Anode Catalysts for the Ethanol Oxidation Reaction in an Alkaline Medium

该项目由美国新罕布什尔大学（UNH）的滕晓伟教授资助，将为直接乙醇碱性燃料电池（DEAFC）反应开发新型钯基二元非均相催化剂。乙醇因其高能量密度、低毒和可获得性而被认为是一种很有前途的能源。然而，当铂作为催化剂时，乙醇氧化反应存在动力学慢、室温下电氧化效率低、成本高等问题。本研究将研究低成本的pd基阳极催化剂在碱性介质中高效氧化乙醇的结构和电活性，并将促进DEAFCs的经济高效使用。为了解和优化DEAFC反应的结构-电活性关系，拟开展的研究包括：(1)利用密度泛函理论（DFT）计算评估pd基二元催化剂的稳定性，并研究其破坏乙醇C-C键的能力；(2)利用综合技术合成和表征pd基催化剂，包括最先进的像差校正扫描透射电子显微镜（STEM）和基于同步加速器的扩展x射线吸收精细结构光谱；(4)通过原位x射线吸收近边结构光谱技术，测量所提出的pd基催化剂在碱性介质中的电活性，了解提高采收率的机理，从而确定最佳的pd基纳米结构，用于在碱性介质中通过C-C键裂解将乙醇高效氧化成CO2。拟议的项目建立在研究人员过去在DFT计算，功能纳米材料，燃料电池催化剂设计以及同步加速器和基于stem的光谱技术方面的成就之上，并整合了一个致力于材料科学和电催化跨学科培训的教育计划。该研究结果将影响DAEFCs技术，使其完全被一种低成本、高效的阳极纳米催化剂取代。该项目的成果将直接支持该国实现能源供应组合多样化的努力，并有助于减少全球碳足迹。更重要的是，这项研究将与一个教育项目相结合，致力于培训和教授学生关于结构-功能关系的力量，不仅是DAEFCs，还有驱动许多过程的基本催化作用。该项目的研究和教育整合将为研究生和本科生提供跨学科的材料科学和电化学结合的努力。此外，学生将有机会在使用最先进设备的国家实验室设施中接受直接培训，并体验如何在其整个职业生涯中利用这些资源来推进研究和技术。

With this project funded by the Chemical Catalysis Program, Prof. Xiaowei Teng of the University of New Hampshire (UNH) will develop new palladium (Pd)-based binary heterogeneous catalysts for direct ethanol alkaline fuel cell (DEAFC) reactions. Ethanol has been considered a promising fuel in power technologies, for its high energy density, low toxicity, and availability from biomass. However, the ethanol oxidation reaction is plagued by slow kinetics, inefficient electro-oxidation at room temperature, and its expense when platinum is used as a catalyst. This proposed work will investigate the structure and electroactivity of low-cost Pd-based anode catalysts with highly-efficient oxidization of ethanol in an alkaline medium, and will advance the cost-effective use of DEAFCs. To understand and optimize the structure-electroactivity relationship for the DEAFC reactions, the proposed research will include: (1) Evaluating the stability of Pd-based binary catalysts and studying their ability to break the C-C bond of ethanol using Density Functional Theory (DFT) calculations, (2) Synthesizing and characterizing Pd-based catalysts using combined techniques, including state-of-the-art aberration-corrected Scanning Transmission Electronic Microscopy (STEM) and synchrotron-based Extended X-ray Absorption Fine Structure spectroscopy, and (4) Measuring electroactivities of the proposed Pd-based catalysts for the DEAFCs in an alkaline medium and understanding the mechanism of the EOR through in-situ X-ray Absorption Near Edge Structure spectroscopy, through which the optimal Pd-based nanostructures will be determined for highly-efficient oxidation of ethanol into CO2 with C-C bond cleavage in an alkaline medium. The proposed project builds upon the researchers' past accomplishments in DFT calculations, functional nanomaterials, catalyst design for fuel cells, and synchrotron- and STEM-based spectroscopic techniques, and integrates an educational program dedicated to the cross-disciplinary training in materials science and electrocatalysis. The outcome of the research will impact DAEFCs technology by completely replacing Pt with an alternative low-cost, highly-efficient anode nanocatalyst. The project outcome will support directly the nation's effort to diversify its energy supply portfolio, and help to reduce the global carbon footprint. More importantly, the research will be coupled with an educational program dedicated to training and teaching students about the power of the structure-function relationship, not only for DAEFCs but also fundamental catalysis that drives so many processes. The research and education integration in this program will provide graduate and undergraduate students with a cross-disciplinary effort that joins material science and electrochemistry. Additionally, the students will have opportunity to receive direct training at national laboratory facilities using state-of-the-art equipment, and to experience how such resources can be utilized throughout their careers to advance research and technology.