Proton Conductive Metal-Organic Frameworks

Abstract

Proton conductors are applied as electrolytes in fuel cells and act as key material in it. We introduced acidic functional groups into the porous coordination polymer (PCP), or metal-organic framework (MOF), and construct proton conductive PCP/MOFs. Novel synthetic method for introducing acidic group in PCP/MOF was invented. Proton conductivity of various PCP/MOF was investigated and some of them showed high proton conductivity up to 8 × 10-3 S cm-1 at ambient temperature. We also investigate the dependency of functional groups onto proton conductivity and found the relationship between proton conductivity, acidity of the functional groups and hydrogen bond network formed inside the pore of PCP/MOF. These PCP/MOF materials have high crystallinity and the frameworks and arrangement of guests in the inner pore were clearly determined by X-ray crystallographic method, and the relationship between proton conductivity and hydrogen bond networks were investigated. This study will provide the novel field for investigating highly proton-conductive materials.