Strategies for the Design and Synthesis of Pt-Based Nanostructured Electrocatalysts in Proton Exchange Membrane Fuel Cells (PEMFCs)

With the rapidly increasing use of fossil fuels, the exploration of various renewable energy sources has become critical. Among these, proton exchange membrane fuel cells (PEMFCs) are garnering significant attention as the next generation of green energy, which is ascribed to their ability to directly convert chemical energy into electricity without emitting pollutants. Specifically, the design and synthesis of effective catalysts are crucial in reducing the cost of commercial PEMFCs because the performance of the oxygen reduction reaction (ORR), which is the most critical reaction in PEMFCs, dictates the overall performance of the cell. Consequently, numerous research groups have recently focused on enhancing the performance and durability of the ORR catalysts. These improvements are being pursued in various fields, including geometry engineering and interfacial engineering. Efforts involve tuning the size and chemical composition of Pt catalysts, as well as developing diverse nanostructures that can be selectively positioned on the crystal surface or alloyed with transition metals. This review delves into the fundamentals of fuel cells and ORR catalysts, which are pivotal energy sources in the realm of green energy. It also outlines a series of catalyst synthesis strategies aimed at boosting their performance. Additionally, this paper offers new insights and highlights key considerations for the future development of platinum-based ORR catalysts in fuel cells.