Achieving Superprotonic Conduction in Metal–Organic Frameworks through Iterative Design Advances

Abstract

Two complementary design strategies, isomorphous ligand replacement and heterocycle doping, have been applied to iteratively enhance the proton conductivity of a metal-organic framework, β-PCMOF2. The resulting materials, PCMOF2¹/₂(Pz) and PCMOF2¹/₂(Tz) (Pz = 1H-pyrazole, Tz = 1H-1,2,4-triazole), have their proton conduction raised almost 2 orders of magnitude compared to β-PCMOF2. The bulk conductivities of these materials are over 10^-1 S cm^-1 at 85 °C and 90% relative humidity (RH), while maintaining the parent MOF structure. A solid state synthetic route for doping 1-D channels is also presented.