Study On Preparation And Proton Conductivity Of Proton-Type Molecular Loaded Porous Framework Materials

In order to cope with the energy crisis and environmental problems,fuel cells have been attracted much attention as an electrochemical device that can utilize clean new energy.Proton exchange membrane fuel cell?PEMFC?can directly utilize hydrogen energy,which has been applied in practice.The improvement of the proton exchange membrane?PEM?performance has become one of the focuses on PEMFC research.In this thesis,the proton molecules?Br?nsted acid,ionic liquid and sulfate?have been loaded into the porous framework materials with good proton conductivity.Br?nsted acids?BAs:H₂SO₄ and H₃PO₄?have been incorporated into SNW-S?high cross-linking degree?and SNW-M?low cross-linking degree?by soaking method,designed as BA@SNW composite.the composites are mixed with PVA/PVP to form hybrid membrane?BA@SNW/PP?.The test results show that H₂SO₄@SNW-M has better proton conductivity(4.96×10^-3 S cm^-1)than that of other composites.By doping H₂SO₄@SNW-M with PVP/PVDP,the resulting hybrid membrane has a proton conductivity of 8.02×10^-3 S cm^-1,which is 2 folds than that of H₂SO₄@SNW-M-and H₃PO₄@SNW-S/M hybrid membranes under the same conditions.Proton ionic liquid?PCILs?have been loaded into bivalent organic frameworks membranes?TP-BT:PCILs?by in-situ method.The rich“acid-base pairs”are formed between the PCILs?[EMIm]HSO₄?and nitrogen-rich skeleton structure?-NH-,-NH₂and C=N⁺?,conducive to the construction of continuous hydrogen bond networks.The synergistic effect enables the TP-BT:PTSA-HSO₄ to have a high proton conductivity of2.87×10^-4 S cm^-1 at low temperature?243 K?and medium humidity.The sulfate@MOF-1 composites have been prepared by imbedding the sulfates into the pores of the metal organic framework?MOF-1?.Due to the strong water absorption of sulfate,the capacity of water vapor adsorption on the composites at high humidity is increased,compared with that of MOF-1.Meanwhile,metal cations and water molecules form hydronium ion clusters as proton transport sites,and SO₄^2-can be employed as the acceptor and donor of protons,and thus enrich the proton-conducting pathways,and improve the proton conduction performance,which also reduce the activation energy of the proton transport process.The test results show that sulfate@MOF-1 composites present higher proton conductivity than MOF-1,and the proton conductivity e of Ce?SO₄?₂@MOF-1 is the highest(323k,4.91×10^-3 S cm^-1).