| Fuel Cell is a new and efficient green and clean energy technology,which can alleviate the energy and environmental problems faced by today's society.Proton exchange membrane fuel cell is a major type of fuel cell,and proton exchange membrane is part of its key components,which can conduct protons,isolate electrons and reactants at the anode and cathode.Therefore,it is of great significance to developing proton exchange membrane with high proton conductivity.In this paper,guest molecular loads or grafts beneficial to proton conduction into the pores or frames of MOF and COF are utilized to improve proton conductivity through the properties of guest molecules.The metal-organic framework MOF-1,CF3SO3H@MOF-1 and H2SO4@MOF-1composites were synthesized by hydrothermal method and simple solvent impregnation method.By comparing the proton conduction properties of these three materials,it was found that the highest electrical conductivity of CF3SO3H@MOF-1 is 16 times that of MOF-1.Then,CS served as the base material and CF3SO3H@MOF-1 was used as the filler to prepare the composite membrane.The results show that 15%CF3SO3H@MOF-1/CS has the highest proton conductivity at 76%RH and 328 K,because CS has more amine groups and CF3SO3H@MOF-1 has sulfonic groups,which can form acid-base pairs and effectively improve proton conductivity.It is 1.01×10-2 S cm-1,twice of CS.Firstly,COF1 was synthesized by solvothermal method and anion sample ILs@COF1-SO3H similar to ionic liquid was synthesized by in-situ synthesis method.Through AC impedance test,it was found that F-COF1-SO3H had better proton conduction performance than P-COF1-SO3H and S-COF1-SO3H,which was 18 times higher than that of COF1(3.5×10-4 S cm-1).A series of composite membranes were obtained by doping with different contents of PVA/PAMPS substrate membranes.The proton conduction performance of 15%wt composite membranes was higher than that of PVA/PAMPS membranes at low humidity(23%RH and 34%RH),among which F-COF1-SO3H@PVA/PAMPS had the best proton performance.Because F has high electronegativity,it can effectively construct a hydrogen bond network,thus realizing proton transmission.Using solvothermal reaction,TPTG-Cl was prepared by schiff base condensation reaction of 1,3,5-triformyl-phlorogllotriol(Tp)and triaminoguanidine nitrate(TG-Cl),and POCl3 was grafted onto TPTG-Cl skeleton by in-situ synthesis method to obtain four kinds of H2PO3@TPTG-Cl composites.At 76%RH and 338 K,H2PO3@TPTG-Cl-3 has the largest proton conductivity(3.04×10-2 S cm-1),which is 3 orders of magnitude higher than TPTG-Cl(2.79×10-5 S cm-1).Most surprisingly,H2PO3@TPTG-Cl-3 also has a certain proton conductivity in anhydrous conditions,even though the conductivity is not high(?10-6 S cm-1).This proton conductor is expected to be used in anhydrous proton exchange membranes in the future. |
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