As the world transitions towards sustainable energy sources, hydrogen-based technologies like proton exchange membrane fuel cells (PEMFCs) and water electrolysis (PEMWEs) are gaining prominence. However, the commercialization of these technologies on a large scale faces challenges primarily due to the high costs associated with noble metal catalysts. Professors Shuiyun Shen and Junliang Zhang from Shanghai Jiao Tong University, China, published a detailed analysis in Nano-Micro Letters on the oxygen transport issues within the catalyst layers of PEM fuel cells and PEMWEs. The article highlights the importance of oxygen transport efficiency in improving the performance and reducing costs of hydrogen technologies. Strategies such as optimizing pore structures, ionomer distribution, and novel carbon supports have shown significant enhancements in oxygen transport within the cathode catalyst layers (CCLs) of PEM fuel cells. Similarly, in PEMWEs, focusing on the formation of high-quality interlayers in anode catalyst layers (ACLs) through ionomer and catalyst optimizations has proven beneficial. Researchers are exploring innovative design approaches, including the controlled growth of pore structures and tailored ionomer-catalyst interactions. By utilizing methods like pore templating techniques and high oxygen permeability ionomers, advancements in bulk and local oxygen transport properties have been achieved. Looking ahead, the review emphasizes the scalability and practical applications of these optimized structures for real-world implementations in PEM fuel cells and PEMWEs. The research also calls for future endeavors in material exploration, structural modifications, and the integration of advanced characterization techniques to further enhance oxygen transport mechanisms. In conclusion, the efforts by Professors Shen and Zhang offer valuable insights and solutions to tackle oxygen transport challenges in hydrogen technologies. Their work sets the stage for the development of high-performance, cost-effective hydrogen technologies, contributing significantly to a sustainable energy future.