Improving Interlayer Interactions in Proton Exchange Membrane Fuel Cell through Carbon Nanotube‐Based Catalyst Design

This review highlights how carbon nanotube (CNT)–based catalyst designs enhance proton exchange membrane fuel cell (PEMFC) performance by improving interlayer interactions. Vertically aligned CNTs facilitate water management, mass transfer, and electron conduction while promoting effective active sites and reducing interfacial resistance. The integrative framework presented provides design principles for durable and efficient next‐generation PEMFC architecture. Abstract Proton exchange membrane fuel cells (PEMFCs) have gained significant attention due to their efficient use of hydrogen energy, high energy density, and zero emissions, making them ideal for future transportation and portable energy frameworks. Despite these advantages, challenges related to catalyst layer design, material durability, and cost‐effectiveness persist. This paper reviews recent advancements in the application of carbon nanotubes (CNTs) in PEMFCs. The study highlights the integration of CNTs at various levels of the membrane electrode assembly (MEA), focusing on both covalent and non‐covalent modification schemes. A particular emphasis is placed on vertically aligned carbon nanotube (VACNT) structures due to their potential to improve electron and mass transport pathways, leading to enhanced fuel cell performance and durability. Additionally, the synergistic effects of blending CNTs with carbon black (CB) are explored to address issues related to interlayer interactions and material conductivity. The review identifies gaps in current research, particularly in understanding the comprehensive impact of CNT modifications on the operational state of the MEA, and proposes new insights and strategies for material design aimed at facilitating the commercialization of PEMFC technology. This review highlights how carbon nanotube (CNT)–based catalyst designs enhance proton exchange membrane fuel cell (PEMFC) performance by improving interlayer interactions. Vertically aligned CNTs facilitate water management, mass transfer, and electron conduction while promoting effective active sites and reducing interfacial resistance. The integrative framework presented provides design principles for durable and efficient next-generation PEMFC architecture. Abstract Proton exchange membrane fuel cells (PEMFCs) have gained significant attention due to their efficient use of hydrogen energy, high energy density, and zero emissions, making them ideal for future transportation and portable energy frameworks. Despite these advantages, challenges related to catalyst layer design, material durability, and cost-effectiveness persist. This paper reviews recent advancements in the application of carbon nanotubes (CNTs) in PEMFCs. The study highlights the integration of CNTs at various levels of the membrane electrode assembly (MEA), focusing on both covalent and non-covalent modification schemes. A particular emphasis is placed on vertically aligned carbon nanotube (VACNT) structures due to their potential to improve electron and mass transport pathways, leading to enhanced fuel cell performance and durability. Additionally, the synergistic effects of blending CNTs with carbon black (CB) are explored to address issues related to interlayer interactions and material conductivity. The review identifies gaps in current research, particularly in understanding the comprehensive impact of CNT modifications on the operational state of the MEA, and proposes new insights and strategies for material design aimed at facilitating the commercialization of PEMFC technology. Advanced Science, EarlyView.