Preventing Catalyst Degradation in Oxygen Reduction: Harnessing Doped Pt3Ni(111) Facets with Pt(111)-Skin

NON-TECHNICAL SUMMARY This grant supports research aimed at enhancing the performance of proton exchange membrane fuel cells (PEMFCs), crucial for green energy initiatives. While PEMFCs produce electricity cleanly, their reliance on costly platinum (Pt)-based catalysts, particularly for the oxygen reduction reaction (ORR) at the cathode with a structural degradation, poses a challenge. The primary goal of this project is to enhance the durability of ORR catalysts while maintaining advanced levels of efficiency and affordability. Focusing on the state-of-the-art Pt3Ni nano-octahedral catalyst, this project employs specialized design and techniques to improve its durability through surface manipulation. By introducing additional metal dopants and adjusting the atomic arrangement on the surface layer, a more enduring catalyst is anticipated. The process involves deliberate design, synthesis, and thorough analysis to comprehend catalyst functionality. Through the development of robust Pt3Ni-based electrocatalysts with lasting efficacy, success in this endeavor could significantly enhance energy conversion processes, benefiting both the environment and society at large. Furthermore, this project has broader implications. Through interdisciplinary collaboration, it offers research opportunities to junior researchers and aims to disseminate findings to the public. By advancing green energy technologies, it seeks to foster a more sustainable future for all. TECHNICAL SUMMARY Green energy solutions, exemplified by proton exchange membrane fuel cells (PEMFCs), hold promise for transforming electricity generation. Recent advancements suggest that enhancing the efficiency and resilience of the oxygen reduction reaction (ORR) can be achieved through techniques such as foreign atom doping or the creation of Pt(111) skin layers on Pt3Ni {111} facets, which are exclusive surfaces of Pt3Ni nano-octahedra. Based on these insights, this project aims to redefine ORR electrocatalysts. Integrating a specific transition metal (M) into Pt3Ni nano-octahedra, along with tailored Pt(111) skins, is anticipated to provide unparalleled ORR electrochemical stability with high activity - the project endeavors to develop catalysts that strike a balance between efficiency and durability by amalgamating these techniques. The approach centers on advancing the M-doped Pt3Ni octahedral nanostructure through surface manipulation. Employing customized synthesis methods and CO-based surface engineering to create Pt(111) skin at an atomic level, the research seeks to identify the optimal foreign element dopant (M) and Pt-skin thickness. Additionally, the project strives to elucidate the dissolution/deposition mechanism on the Pt3Ni(111)@Pt(111) reaction platform when incorporating various dopants. Objectives also include amplifying ORR efficiency, validating durability, and understanding electrochemical degradation. Central to the research is the focus on devising an innovative strategy to mitigate catalyst degradation, potentially setting new benchmarks for catalyst activity and longevity. With these objectives and four work packages (i.e., crafting M-doped Pt3Ni nano-octahedra, assessing ORR performance, understanding surface structure dynamics and ORR degradation processes, and developing cost-effective catalyst analogs), this project is expected to deliver more efficient ORR catalysts, expanding the horizons of electrocatalysis and driving innovation in energy conversion. 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.