Cobalt phosphonate, preparation method thereof and application of cobalt phosphonate as proton conducting material in wide temperature range

Abstract

The invention discloses cobalt phosphonate, a preparation method thereof and an application of the cobalt phosphonate as a proton conducting material in a wide temperature range. The molecular expression of cobalt phosphonate is [Co(4,4'-bipy)(H2O)4]*[Co(4,4'-bipy)2(H3O)2(H2O)2]]*2H4bmt*6H2O, wherein H4bmt is a ligand (benzene-1,3,5-trimethyl(methylene))triphosphate(H6bmt) with two protons removed, and 4,4'-bipy is a 4,4'-bipyridine molecule. The preparation method of the cobalt phosphonate includes carrying out hydrothermal reaction on an aqueous solution containing H6bmt, 4,4'-bipyridine andCo(OAc)2*4H2O with a pH value of 2-9 to obtain the product. Cobalt phosphonate contains a large number of water molecules and phosphonic acid groups as well as abundant hydrogen bond networks, as a proton conducting material for water medium, cobalt phosphonate has excellent conductivity in a wide working temperature range of 287-373K, and moreover, cobalt phosphonate can maintain stable structure and very high conduction value even after being repeatedly used at 373K and 98% relative humidity (RH), so that the cobalt phosphonate is a potential proton conducting material.

Description

technical field

[0001] The present invention relates to a proton conduction material, in particular to a metal ion with cobalt (II) as the center, 4,4'-bipyridine and [H 4 bmt] 2- The invention relates to a cobalt phosphonate (cobalt-phosphonic acid complex) composed of a ligand, and also relates to a preparation method of the cobalt phosphonate and the application of the cobalt phosphonate as a proton conduction material in a wide working temperature range, belonging to the technical field of fuel cells. Background technique

[0002] Proton-conducting materials have attracted extensive attention due to their potential applications in electrochemical devices, sensors, and fuel cells. Currently, the commercialized perfluorosulfonic acid hydration membrane has a proton conductivity of 10 at 60-80°C and 98% RH. -2 ~10 -1 S cm -1 . However, the price of perfluorosulfonic acid is very high, and it is unstable when used above 100°C, which seriously affects the proton conducti...

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