| Affiliation: | 1. College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816 China Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, CH-1015 Switzerland;2. College of Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 211816 China;3. Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, CH-1015 Switzerland |
| Abstract: | Solid-state proton conductors based on the use of metal–organic framework (MOF) materials as proton exchange membranes are being investigated as alternatives to the current state of the art. This study reports a new family of proton conductors based on MIL-101 and protic ionic liquid polymers (PILPs) containing different anions. By first installing protic ionic liquid (PIL) monomers inside the hierarchical pores of a highly stable MOF, MIL-101, then carrying out polymerization in situ, a series of PILP@MIL-101 composites was synthesized. The resulting PILP@MIL-101 composites not only maintain the nanoporous cavities and water stability of MIL-101, but the intertwined PILPs provide a number of opportunities for much-improved proton transport compared to MIL-101. The PILP@MIL-101 composite with HSO4− anions shows superprotonic conductivity (6.3 × 10−2 S cm−1) at 85 °C and 98% relative humidity. The mechanism of proton conduction is proposed. In addition, the structures of the PIL monomers were determined by single crystal X-ray analysis, which reveals many strong hydrogen bonding interactions with O/N H···O distances below 2.6 Å. |
