Development of Ultra-low Loading Platinum Alloy Cathode Catalysts for PEM Fuel Cells: Theoretical and Experimental Studies

本研究将为开发用于氧还原反应（ORR）的质子交换膜（PEM）燃料电池阴极催化剂提供科学和工程基础，该催化剂具有超低铂负载和更高的耐久性。这些催化剂有望具有快速的反应速率和良好的稳定性，这对于开发用于可持续能源系统的下一代燃料电池至关重要。采用超低铂负载的碳复合催化剂（CCC）合成智能汞杂化阴极催化剂（HCC），该催化剂具有高含量的活性吡啶氮位点，将用作超低铂负载的载体，取代目前商用催化剂中使用的炭黑。不含贵金属的CCC除了自身对催化剂整体活性的贡献外，还会通过协同效应提高Pt和Pt合金（如Pt- co /CCC、Pt- fe /CCC、Pt- ni /CCC）的活性。将使用第一性原理数学模型和密度泛函理论（DFT）计算来帮助理解HCC催化剂上的氧还原动力学。结构-性能关系将建立使用广泛的电化学和表面表征技术。这些研究将为新的合成方法的发展创造一个框架，以制备超低铂负载的高活性和稳定的ORR催化剂。更广泛的影响考虑到全球铂储量较低（3万吨未探明储量），本研究中提出的混合阴极催化剂（HCC）有可能降低PEM燃料电池的成本和这种贵金属的消耗。将为研究生和本科生开设量子化学和材料表面表征以及材料科学和电化学工程的跨学科课程。通过培训学生以小组为基础解决问题，帮助学生掌握技术和时间管理技能，并挑战他们完成与氧还原电催化剂相关的项目，将开发项目加速从被动学习者向科学家和工程师的转变。此外，该项目将提高社区对下一代能源技术和就业机会的认识，并促进来自代表性不足群体的学生参与这些活动。

0966956PopovThe proposed research will establish a scientific and engineering basis for the development of proton exchange membrane (PEM) fuel cell cathode catalysts having ultra-low Pt loadings and increased durability for the oxygen reduction reaction (ORR). These catalysts are expected to have fast reaction rates and good stability that are essential for developing next generation fuel cells for sustainable energy systems. Intellectual MeritHybrid cathode catalysts (HCC) will be synthesized using a carbon composite catalyst (CCC) with an ultra-low loading of Pt. The CCC has a high content of active pyridinic nitrogen sites, and will be used as a support for ultra-low loading of platinum instead of carbon black, which is currently used in the commercial catalysts. Besides its own contribution to the overall catalyst activity, the noble metal free CCC will enhance the activity of Pt and Pt alloys (e.g., Pt-Co/CCC, Pt-Fe/CCC, Pt-Ni/CCC) through synergistic effects. A first-principles mathematical model and density functional theory (DFT) calculations will be used to help understand the oxygen reduction kinetics on the HCC catalysts. Structure-property relationships will be established using a wide range of electrochemical and surface characterization techniques. These studies will create a framework for the development of novel synthesis procedures to prepare highly active and stable catalysts for ORR with ultra-low Pt loading. Broader ImpactsGiven the world's low platinum reserves (30,000 tons of unproven reserves), the hybrid cathode catalyst (HCC) proposed in this study has the potential to reduce both the cost of the PEM fuel cell and consumption of this precious metal. Interdisciplinary courses at both the graduate and undergraduate levels in quantum chemistry & material surface characterization, as well as materials science & electrochemical engineering, will be developed. Programs will be developed to accelerate the transition from passive learners to scientists and engineers by training students in group-based problem solving, helping students acquire technical and time management skills, and by challenging them to complete a project related to electrocatalysts for oxygen reduction. In addition, the program will increase community awareness of next-generation energy technology and career opportunities, and promote the involvement of students from under-represented groups in these activities.