EAGER:CAS-Climate: Novel Non-Precious Metal Catalysts for Oxygen Reduction Reaction

在化学系化学催化项目的支持下，位于派恩海崖的阿肯色州大学的Daoyuan Wang和位于小石城的阿肯色州大学的Anindya Ghosh正在开发基于地球上丰富的金属的燃料电池应用新催化剂。大多数市售的氢氧燃料电池由昂贵的铂（Pt）阳极和阴极组成。因此，存在制备Pt基电极的合适替代物的重要动机。Wang和Ghosh合作团队将合成支撑在多壁碳纳米管和石墨烯材料上的非贵金属络合物，并将其作为质子交换膜燃料电池（PEMFC）中氧还原反应（ORR）的催化剂进行评估。这项研究预计将影响可再生能源和燃料电池技术，对可持续性产生重要影响。理工科中人数不足的少数民族学生将积极参与研究。该教育计划将包括对阿肯色州周边学校和教育中心的外展活动，以向教师、学生和公众推广绿色化学和可持续能源。该项目旨在开发用于ORR反应的新型非贵金属催化剂，催化剂来自含有可调酰胺配体的金属络合物。Wang和Ghosh的合作研究团队将设计配体，这些配体将提供可调的配位环境，以稳定处于不寻常氧化态的金属中心，并有利于氧还原。基于酰胺的络合物将被设计为正方形平面或包含不同几何形状的弱结合配体，以允许氧配位到金属中心以便于其还原，同时提高更高的电流密度和更低的过电压。金属络合物将负载在碳纳米材料上。然后将这些负载的系统用廉价的生物启发聚合物（如聚多巴胺及其衍生物）涂覆，并评估它们在宽pH范围内为金属络合物提供增强的氧化和水解稳定性以及显著改善ORR活性的潜力。将进行改变该三组分系统（金属络合物、碳质载体、聚合物涂层）的各个组分的比率和/或类型，并通过实验和电化学评估结果。重点将放在理解的催化剂的活性位点的结构和这些新系统启用的ORR的机制。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support from the Chemical Catalysis Program in the Division of Chemistry, Daoyuan Wang of the University of Arkansas at Pine Bluff and Anindya Ghosh of the University of Arkansas at Little Rock are developing new catalysts based on earth-abundant metals for fuel cell applications. Most commercially available hydrogen-oxygen fuel cells consist of expensive platinum (Pt) anodes and cathodes. Thus, a significant motivation for preparing suitable replacements for the Pt-based electrodes exists. The Wang and Ghosh collaborative team will synthesize non-precious metal complexes supported on multi-walled carbon nanotube and graphene materials, and evaluate them as catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). This research is anticipated to impact renewable energy and fuel cell technology, with important implications for sustainability. Underrepresented minority students in science and engineering will actively participate in the research. The educational program will include outreach activities to surrounding schools and educational centers in Arkansas to promote green chemistry and sustainable energy to teachers, students, and the general public. This project aims to develop new non-precious metal catalysts for the ORR reaction, with the catalysts derived from metal complexes containing tunable amide ligands. The collaborative research teams of Wang and Ghosh will design ligands that will provide tunable coordination environments for the stabilization of the metal centers in unusual oxidation states and favoring oxygen reduction. The amide-based complexes will be designed to be either square planar or to contain weakly bound ligands in different geometries, to allow for oxygen coordination to the metal center for its facile reduction while enhancing higher current density and lower overvoltage. The metal complexes will be supported on carbonaceous nanomaterials. These supported systems will then be coated with inexpensive and bioinspired polymers such as polydopamine and its derivatives, and evaluated for their potential to provide enhanced oxidative and hydrolytic stability to the metal complexes over a wide pH range and to significantly improve ORR activity. Varying the ratios and/or types of the individual components of this three-component system (metal complex, carbonaceous support, polymer coating) will be performed and the results evaluated experimentally and electrochemically. An emphasis will be placed on understanding the structure of the active sites of the catalysts and the mechanisms of the ORR enabled by these new systems. The research activities and their relationship to environmental sustainability will be incorporated into the planned outreach activities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.