A Metal–Organic Framework Impregnated with a Binary Ionic Liquid for Safe Proton Conduction above 100 °C

To develop proton‐conducting materials under low‐humidity conditions and at moderate working temperature still remains challenging for fuel‐cell technology. Here, a new type of proton‐conducting material, EIMS‐HTFSA@MIL, which was prepared by impregnating the binary ionic liquid, EIMS‐HTFSA (EIMS=1‐(1‐ethyl‐3‐imidazolium)propane‐3‐sulfonate; HTFSA= N , N ‐bis(trifluoromethanesulfonyl)amide), into a mesoporous metal–organic framework, MIL‐101 ([Cr 3 F(H 2 O) 2 O(BDC) 3 ⋅ n H 2 O] ( n ≈0.25, BDC=1,4‐benzenedicarboxylate)) is reported. By taking advantage of the ionic‐liquid properties, such as high thermal stability, non‐volatility, non‐flammability, and low corrosivity, EIMS‐HTFSA@MIL shows potential application as a safe electrolyte in proton conduction above 100 °C.