BRIGE: One-Dimensional PdFe Core- Pt Shell Nanowires for Oxygen Reduction Reaction

1032547 Li NSF-BRIGE提案的研究目标是研究一种新型的一维轴向PdFe核- Pt壳纳米线，其具有有利的晶体学刻面和调谐的电子性质，并且可以用作电化学能量转换和存储设备的有效阴极催化剂。总体目标是获得原子和纳米尺度金属纳米催化剂受控湿化学合成的基本认识，并获得多金属电催化体系结构-催化功能关系的知识。PI的职业目标是在密歇根理工大学（Michigan Tech）建立世界一流的纳米电化学能源计划，将催化和清洁能源与工程相结合，并将教学/培训/学习与研究相结合。 可持续地满足人类的能源需求已被确定为未来50年的主要研究挑战。在没有卡诺限制的情况下，电化学能量装置以高理论效率直接将燃料（即H2、乙醇、锌等）的化学能转化为电。然而，阴极处的氧还原反应（ORR）的缓慢动力学一直是一个长期存在的科学问题，其显著降低了电化学能量转换效率。PI的团队已经开始了对“金属纳米结构的精确制备”的严格研究，他们开发了一种湿化学方法来合成具有大电化学表面积和良好耐久性的一维PtFe/PdFe合金纳米线。工作假设是PdFe核- Pt壳纳米线可以1）由于表面上更活跃的结晶学小面Pt {111}和表面Pt原子的优化的d带中心而大大改善ORR活性; 2）由于较少的热驱动聚结而显著增强耐久性。为了验证这一假设，PI建议在电化学能源纳米结构催化剂领域进行变革性研究。本项目的具体研究任务包括：1）碳载一维PdFe核- Pt壳纳米线（PdFe@Pt-NW/C）催化剂的精确合成和全面表征; 2）研究PdFe@Pt-NW/C催化剂在三室电池中的电化学性能; 3）在真实的电化学能源装置中的ORR和耐久性研究。这个NSF-BRIGE提案非常适合PI的长期研究兴趣，即研究新型纳米工程材料的控制合成并了解其电催化反应机制。 更广泛的影响：项目活动将通过密歇根理工大学的现有基础设施，对五大湖地区的研究、教育和推广工作产生广泛影响。研究活动所产生的知识和技术将促进新型催化剂在原子和纳米尺度上的精确合成，并加深对多金属催化剂结构-催化功能关系（具体而言，“Pt皮-PdFe基底相互作用”与ORR活性）的理解。这项研究工作将启动与工业界的密切研究合作。它将推动先进材料的开发，提供新的发现，加强密歇根理工大学的基础设施和技术转让，并加强密歇根理工大学正在进行的“可持续能源”活动。这项研究也将有助于提升清洁电化学能源器件的制造技术。特别是，它将支持国家？中国正在努力使能源供应多样化，减少对外国石油的依赖。拟议的教育计划是设计和制作一本清洁能源工作手册。该手册将作为本科生和中学生清洁能源和催化教育的独特材料。一个主要观众将包括6 - 12年级的学生谁参加密歇根理工大学现有的暑期青年计划（SYP）和现有的密歇根大学计划（MICUP），其中大多数学生主要是从传统上代表性不足的群体在科学和工程不同的社区大学生群体绘制。拟议的研究和教育计划将有助于通过致力于尖端的纳米催化剂技术，将更多来自传统上代表性不足的群体（女性，非洲裔美国人，西班牙裔和美洲原住民，残疾人）的工程师带入工程领域。将年轻学生暴露在催化，清洁能源和纳米技术研究环境中将激发他们对科学，工程和技术的好奇心和兴趣，并通过可持续地提供一些多样化的下一代研究人员来造福社会，这些研究人员将成为未来科学劳动力的榜样。

1032547Li The research objective of the NSF-BRIGE proposal is to investigate a novel one-dimensional axial PdFe core - Pt shell nanowires, which have advantageous crystallographic facets and tuned electronic properties, and can be used as efficient cathode catalysts for electrochemical energy conversion and storage devices. The overall goals are to acquire fundamental understanding of controlled wet-chemical synthesis of metallic nanocatalysts at the atomic and nano- scale, and gain knowledge of structure-catalytic functionality relationship of multi-metallic electrocatalytic systems. The career goal of the PI is to establish a world-class Nano Electrochemical Energy Program at Michigan Technological University (Michigan Tech) incorporating catalysis and clean energy with engineering, and integrating teaching / training / learning with research. Intellectual merits: Sustainably meeting humanity's energy needs has been identified as a primary research challenge for the next fifty years. Without Carnot limitation, electrochemical energy devices directly convert chemical energy of fuels (i.e. H2, ethanol, Zinc, etc) into electricity with high theoretical efficiency. However, the sluggish kinetics of oxygen reduction reaction (ORR) at cathode has been a long-standing scientific issue, which significantly reduces the electrochemical energy conversion efficiency. The PI's group has started a rigorous research on "accurate preparation of metallic nanostructures", and they have developed a wet-chemical approach to synthesis of 1-D PtFe/PdFe alloy nanowires with large electrochemical surface area and good durability. The working hypothesis is that PdFe core- Pt shell nanowires can 1) greatly improve ORR activity due to more active crystallographic facet Pt {111} on surface and optimized d-band center of surface Pt atoms; 2) significantly enhance durability due to less thermal-driven coalescence. To test this hypothesis, the PI proposes to conduct transformative research in the area of nanostructured catalysts for electrochemical energy. The specific research tasks of this proposal include: 1) precise synthesis and full characterization of carbon supported 1-D PdFe core- Pt shell nanowires (PdFe@Pt-NW/C) catalysts, 2) investigate electrochemical performance of PdFe@Pt-NW/C in three-compartment-cell, and 3) ORR and durability study in real electrochemical energy device. This NSF-BRIGE proposal fits well into the PI's long-term research interest of studying controlled synthesis of novel nanoengineered materials and understanding their electrocatalytic reaction mechanisms. Broader Impacts: The project activities will have a broad impact on research, education and outreach efforts in the Great Lakes Region through Michigan Tech's established infrastructure. The knowledge and technology generated from the research activities will advance accurate synthesis of novel catalysts at the atomic and nano- scale, and deepen understanding of structure-catalytic functionality relationship (specifically, "Pt skin-PdFe substrate interaction" with ORR activity) of multimetallic catalysts. This research effort will initiate close research collaborations with industry. It will propel development of advanced materials, deliver new discoveries, enhance Michigan Tech's infrastructure and technology-transfer, and strengthen Michigan Tech's on-going "sustainable energy" activities. This research will also help upgrade fabrication techniques of clean electrochemical energy devices. In particular, it will support the nation?s efforts to diversify its energy supply and reduce dependence on foreign oil. The proposed educational plan is to design and produce a Clean Energy Workbook. The Workbook will serve as a unique material in clean energy and catalysis education for undergraduate and secondary students. One primary audience will include diverse groups of 6th-12th grade students who participate in Michigan Tech's existing summer youth program (SYP) and diverse community college students in the existing Michigan College & University Program (MICUP), in which the majority of students are primarily drawn from traditionally underrepresented groups in science and engineering. The proposed research and education plan will help to bring more engineers from groups traditionally underrepresented (female, African American, Hispanic and Native American, disabled) into engineering areas by working on cutting-edge Nanocatalyst Technology. Exposing young students to the catalysis, clean energy, and nanotechnology research environment will inspire their curiosity and interest in science, engineering, and technology, and benefit society by sustainably supplying a number of diverse, next generation researchers that serve as role models for the scientific workforce of the future.