The advantages of high-temperature proton exchange membrane fuel cells lie in their applicability to heavy machinery, requiring high power density. However, the commercial membrane electrode assembly (MEA) with polytetrafluoroethylene binders in catalyst layer (CLs) has low cell performance. In this study, hydrophobic mesoporous silica (HM-SiO) is successfully prepared and incorporated into CL with a novel bipyridyl polybenzimidazole (Py-PBI) binders reported in our previous work. The HM-SiO can partially react with phosphoric acid (PA) to generate colloidal silicophosphoric acid. This can immobilize PA within the CL, prevent it from poisoning the platinum-carbon (Pt–C) catalyst. Owing to the partial dissolution of HM-SiO, the HM-SiO is advantageous for decreasing the resistance to oxygen and steam transport. The MEA with 15 wt% HM-SiO exhibits a peak power density of 714 mW cm at 160 °C under 0.6 mg cm Pt, which is a considerable improvement compared with that with commercial binder (260 mW cm). The MEA with 15 wt% HM-SiO also demonstrates excellent stability in long-term stability test. Controlling PA distribution and gas transport by using HM-SiO is an effective strategy for improving the cell performance.

中文翻译：

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增强电池性能：将疏水性介孔二氧化硅纳入催化剂层的三相边界

高温质子交换膜燃料电池的优点在于适用于需要高功率密度的重型机械。然而，催化剂层（CL）中含有聚四氟乙烯粘合剂的商用膜电极组件（MEA）电池性能较低。在这项研究中，成功​​制备了疏水性介孔二氧化硅（HM-SiO），并将其与我们之前报道的新型联吡啶聚苯并咪唑（Py-PBI）粘合剂结合到CL中。 HM-SiO可以与磷酸（PA）部分反应生成胶体硅磷酸。这可以将 PA 固定在 CL 内，防止其中毒铂碳 (Pt–C) 催化剂。由于HM-SiO的部分溶解，HM-SiO有利于降低对氧气和蒸汽传输的阻力。含有 15 wt% HM-SiO 的 MEA 在 0.6 mg cm Pt 下在 160 °C 下表现出 714 mW cm 的峰值功率密度，与商用粘合剂 (260 mW cm) 相比有相当大的改进。含有 15 wt% HM-SiO 的 MEA 在长期稳定性测试中也表现出优异的稳定性。使用HM-SiO控制PA分布和气体传输是提高电池性能的有效策略。