Abstract Acid-alkaline amphoteric water electrolysis is considered as a potential approach for efficient hydrogen production at industrial scale; however, to date synthesized or post-functionized polymer for constructing membranes can hardly meet the requirement of either electrolysis performance or durability aspects. Herein, we synthesize a series of H2SO4-doped PBI-based membranes, including poly (2,2’-(m-phenylene)-5,5’-bibenzimidazole) (m-PBI) and poly (4,4’-diphenylether-5,5’-bibenzimidazole) (OPBI), for application in acid-alkaline amphoteric water electrolysis system. The H2SO4 doping content, water uptake, swelling ratio, chemical durability and proton conductivity of m-PBI and OPBI membranes are characterized and compared with the perfluorinated sulfonated membrane (Nafion 115). Specifically, the m-PBI membrane doped in 3.0 M H2SO4 attains a current density of 800 mA cm−2 at cell voltage of 2.0 V at 60 °C when applied in an amphoteric water electrolysis, which is superior to the performance of commercial units. Moreover, such system reveals a long-term stability when operating at the current density of 100 mA cm−2 for 40 h, with an energy consumption of 3.35 kWh m−3 H2, offering a possibility for low-energy consumption and scaled hydrogen production technology.

中文翻译：

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H2SO4 掺杂聚苯并咪唑膜用于酸碱两性水电解制氢

摘要 酸碱两性水电解被认为是工业规模高效制氢的潜在途径。然而，迄今为止，用于构建膜的合成或后功能化聚合物难以满足电解性能或耐久性方面的要求。在此，我们合成了一系列 H2SO4 掺杂的基于 PBI 的膜，包括聚 (2,2'-(m-亚苯基)-5,5'-联苯并咪唑) (m-PBI) 和聚 (4,4'-二苯醚) -5,5'-联苯并咪唑) (OPBI)，用于酸碱两性水电解系统。表征了 m-PBI 和 OPBI 膜的 H2SO4 掺杂含量、吸水率、溶胀比、化学耐久性和质子传导率，并与全氟化磺化膜 (Nafion 115) 进行了比较。具体来说，m-PBI膜掺杂了3。当应用于两性水电解时，0 M H2SO4 在 2.0 V 的电池电压和 60 °C 下获得 800 mA cm-2 的电流密度，这优于商业装置的性能。此外，该系统在 100 mA cm-2 的电流密度下运行 40 h 时表现出长期稳定性，能耗为 3.35 kWh m-3 H2，为低能耗和规模化制氢提供了可能技术。