Achieving High Intrinsic Proton Conductivity via Functionalization of MOF-808 by Ionic Liquid
Junchao Jia, Xiaomin Li, Huan Wu, Qing Huang, Junkuo Gao
Abstract
Achieving high intrinsic proton conductivity is essential for the development of stable proton conductors in proton exchange membrane fuel cells. Herein, an ionic liquid (IL) with a hydrosulfate anion, an imidazole ring, and a sulfonate group beneficial to proton transfer was used to functionalize a metal–organic framework (MOF-808) by replacing the formates coordinated with Zr. The obtained MOF-808-IL exhibits high intrinsic proton conductivity of 1.28 × 10 –1 S cm –1 at 60 °C and 100% relative humidity (RH), which exceeds those of most of the MOF-based proton conductors. Moreover, the proton transfer mechanism has been elucidated by the combination of the crystal structure and variable temperature Fourier transform infrared spectra. This study provides a strategy for achieving ultrahigh proton conductivity and a model for analyzing the proton conducting mechanism.