Superprotonic Conductivity of a Functionalized Metal–Organic Framework at Ambient Conditions
Xiaomin Li, Yameng Wang, Yongbiao Mu, Jiang Liu, Lin Zeng, Ya‐Qian Lan
Abstract
Seeking fast proton transport pathways at ambient conditions is desirable but challenging. Here, we report a strategy to synthesize a composite material with a polyoxometalate (POM) and an ionic liquid (IL) confined in stable metal–organic framework (MOF) channels through electrostatic interaction. The obtained SO3H-IL-PMo12@MIL-101 possesses fast proton transfer, and its proton conductivity can reach 1.33 × 10–2 S cm–1 at ambient conditions (30 °C, 70% relative humidity (RH)), which is the highest value among the MOF-based proton conductors operated in an ambient environment. Therefore, it has the potential of becoming a room-temperature proton conductor without a humidifier. Importantly, the composite material is further fabricated into a composite membrane for proton-exchange membrane fuel cells (PEMFCs), which can deliver a power density of 0.93 mW cm–2 at 30 °C and 98% RH. This result can lay a fundamental basis for the application of MOF-based proton conductors in the area of electrochemical energy conversion.