The development of rapid and dependable proton transport channels is crucial for proton exchange membrane fuel cells (PEMFCs) operating in low humidity conditions. Herein, a metal–organic framework (NH-Zr framework) consisting of 1H-pyrazole-3, 5-dicarboxylic acid (PZDC), and zirconium chloride octahydrate (ZrOCl₂·8H₂O) rich in basic sites was in situ constructed in a perfluorosulfonic acid (PFSA) solution, and hybrid proton exchange membranes were prepared (PFSA-NH-Zr). The introduced NH-Zr framework successfully induced proton conducting groups (-SO₃H) reorganization along the NH-Zr framework, resulting in the formation of fast ion transport channels. Meanwhile, under low humidity, the acid–base pairs between N–H (NH-Zr framework) and -SO₃H (PFSA) promoted the protonation/deprotonation and the subsequent proton leap via the Grotthuss mechanism. Especially, the hybrid membrane PFSA-NH-Zr-1 with suitable NH-Zr content had a promising proton conductivity of 0.031 S/cm at 80 °C, 40% relative humidity (RH), and 0.292 S/cm at 80 °C, 100% RH, which were approximately 33% and 40% higher than the pristine PFSA membrane (0.023 S/cm and 0.209 S/cm), respectively. In addition, the maximum power density of the hybrid proton exchange membrane was 0.726 W/cm², which was nearly 20% higher than the pristine PFSA membrane (0.604 W/cm²) under 80 °C, 40% RH. Thus, PFSA-NH-Zr may be promising membrane materials for potential applications in fuel cells. This work established a referable strategy for developing high-performance proton exchange membranes under low RH conditions.

Graphical Abstract

中文翻译：

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通过用于燃料电池的原位酸碱对金属有机骨架对全氟磺酸膜进行质子传导通道工程

快速可靠的质子传输通道的发展对于在低湿度条件下运行的质子交换膜燃料电池 (PEMFC) 至关重要。在此，原位构建了由 1H-pyrazole-3, 5-二羧酸 (PZDC) 和富含碱性位点的氯化锆八水合物 (ZrOCl 2 ·8H 2 O) 组成的金属有机骨架（NH - _Zr骨架_）全氟磺酸 (PFSA) 溶液，并制备了混合质子交换膜 (PFSA-NH-Zr)。引入的 NH-Zr 框架成功地诱导了质子传导基团 (-SO ₃ H) 沿 NH-Zr 框架的重组，从而形成了快速离子传输通道。_{同时，在低湿度下，N–H（NH-Zr骨架）和-SO 3}之间的酸碱对H (PFSA) 通过 Grotthuss 机制促进质子化/去质子化和随后的质子跃迁。特别是，具有合适 NH-Zr 含量的杂化膜 PFSA-NH-Zr-1 在 80 °C、40% 相对湿度 (RH) 和 80 °C 时具有 0.031 S/cm 的有希望的质子电导率和 0.292 S/cm , 100% RH，分别比原始 PFSA 膜（0.023 S/cm 和 0.209 S/cm）高约 33% 和 40%。此外，杂化质子交换膜的最大功率密度为0.726 W/cm ²，比原始PFSA膜（0.604 W/cm ^{2 ）高出近20%}) 在 80 °C，40% 相对湿度下。因此，PFSA-NH-Zr 可能是一种很有前途的膜材料，可用于燃料电池的潜在应用。这项工作为在低 RH 条件下开发高性能质子交换膜建立了可参考的策略。

图形概要