State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian, 116024, P. R. China.
Institute for Energy Research, Jiangsu University, 301 Xuefu Road, Zhenjiang, 212013, P. R. China.
Small. 2023 May;19(21):e2207155. doi: 10.1002/smll.202207155. Epub 2023 Feb 25.
Catalyst coated membrane (CCM) is the core component of proton exchange membrane fuel cells and is routinely fabricated by spraying Pt/C slurries onto membrane, resulting in low activity and thick catalyst layer (CL, 5-10 µm) with an unaffordable Pt loading of 0.2-0.4 mg cm and a large mass transfer resistance at cathode. Highly active ultrathin ultralow-Pt CL (UUCL) is urgently required, but remains rare. Herein, wet-chemical direct growth of UUCLs on both sides of membrane to achieve integrated ultrathin ultralow-Pt catalyst coated membranes (UUCCMs) with a cathodic CL thickness of 79.7 ± 15.0 nm and a Pt loading of 20.2 ± 1.6 µg cm is reported. The key to this unique fabrication is the release of proton from membrane to regioselectively initiate the growth of interconnected Pd nanoneedle clusters array on membrane, followed by high-density deposition of Pt nanoparticles on Pd (Pt/Pd UUCLs). The single cell of UUCCMs exhibits the highest mass peak power density of 59.9 W mg in the literature. The exceptional activity originates from high electrochemically active surface area, remarkable oxygen reduction reaction activity closely correlated with strain, and electronic effect at Pt/Pd interface, as well as improved mass transfer and optimal water management.
催化剂涂覆膜（CCM）是质子交换膜燃料电池的核心组件，通常通过将 Pt/C 浆料喷涂在膜上来制备，这导致催化剂层（CL）的活性低且较厚（5-10μm），Pt 负载量高（0.2-0.4mgcm），且在阴极处存在较大的传质阻力。急需高活性的超薄超低 Pt CL（UUCL），但仍很少见。本文报道了在膜的两侧通过湿化学直接生长 UUCL，以实现集成的超薄超低 Pt 催化剂涂覆膜（UUCCM），其阴极 CL 厚度为 79.7±15.0nm，Pt 负载量为 20.2±1.6μgcm。这种独特制造的关键是从膜中释放质子，从而在膜上选择性地引发相互连接的 Pd 纳米针簇阵列的生长，然后在 Pd 上高密度沉积 Pt 纳米颗粒（Pt/Pd UUCLs）。UUCCM 的单电池在文献中表现出最高的质量峰值功率密度为 59.9Wmg。这种优异的活性源于高电化学活性表面积、与应变密切相关的显著氧还原反应活性、Pt/Pd 界面的电子效应，以及改进的传质和优化的水管理。
