Effect of gas diffusion layer surface property on platinum nanowire array electrode performance in proton exchange membrane fuel cells

3D-ordered catalyst electrodes have been recognized as one effective strategy to reach high current density operation for proton exchange membrane fuel cell (PEMFC) applications. Gas diffusion electrodes (GDEs) with platinum nanowire arrays in-situ grown on gas diffusion layer (GDL) surface is an important contribution in this area, but the performance is highly dependent on the GDL surface properties. In this study, the GDLs available in the market are systematically investigated, with a focus on the influence of the GDL surface properties on the in-situ growth of Pt nanowire arrays to fabricate GDEs as cathodes for PEMFCs. The experimental results indicate that mesopores especially micropores play a key role. They enable a hydrophilic surface for the isopropanol pretreated GDL, facilitating the in-situ growth of Pt nanowires to form a uniform array with a large electrochemical surface area (ECSA), finally leading to a high-power density. With Freudenberg H24CX483 carbon paper GDL, the highest power density of 0.9 W cm−2 is achieved. The understanding achieved here could be further used to develop novel GDLs for fabricating the next generation of electrodes for large current density operations.

三维有序催化剂电极已被视为实现质子交换膜燃料电池（PEMFC）应用中高电流密度运行的一种有效策略。在气体扩散层（GDL）表面原位生长铂纳米线阵列的气体扩散电极（GDEs）是该领域的一项重要成果，但性能在很大程度上取决于GDL的表面性质。在本研究中，对市场上可获得的GDL进行了系统研究，重点关注GDL表面性质对铂纳米线阵列原位生长的影响，以制备用作PEMFC阴极的GDE。实验结果表明，介孔尤其是微孔起着关键作用。它们使经异丙醇预处理的GDL表面具有亲水性，有利于铂纳米线的原位生长，从而形成具有大电化学表面积（ECSA）的均匀阵列，最终实现高功率密度。使用科德宝H24CX483碳纸GDL，实现了0.9 W cm⁻²的最高功率密度。在此获得的认识可进一步用于开发新型GDL，以制造用于大电流密度运行的下一代电极。