Cooperative proton transportation based on the reversible single crystal–single crystal transformation in a highly water-stable Cu-MOF with its facile and scalable preparation

Abstract

A Cu-MOF with excellent acid–base stability in boiling water was constructed under mild conditions. This MOF was very suitable for scaled-up preparation, and exhibits distinct proton conductivity at temperatures above and below 75 °C.

Two-dimensional coordination polymers with high proton conductivity and ultrafast highly efficient molecular sieving constructed by the structural inductive effect

“…The hydrogen bond network manifests a promising proton-conducting material since the highly ordered structures are in favour of proton transfer in the solid as identified in our previous work. 22 As we expected, the experimental determination (Fig. 3 and S17 †) indicated that HNNU-1α to 1γ display a surprising proton conductivity of ca.…”

“…2.2 × 10 −2 , 4.9 × 10 −5 and 3.0 × 10 −4 S cm −1 at 90 °C and 98% relative humidity (RH), respectively. Note that the conductivity of HNNU-1α is much higher than those of other proton conductors having carboxylic acid (−10 −3 S cm −1 ), 14,22,30 and far beyond the range (10 −8 -10 −5 S cm −1 ) of MIL-53 constructed by the H 4 BTPC ligand. 31 The proton conductivities of HNNU-1β and 1γ are close to that of carboxylic acid-functionalized MIL-53.…”

“…21 For example, we have reported that a zwitterion pyridiniumolate (TTP) can be applied as a new SIA to tune the spatial structures and the pore volume ratio of the synthesized MOFs, 21 and confirmed that triangular TTP, quadrangular or other shaped zwitterion pyridiniumolates and camphoric acid can play the same role to induce and tune the aimed coordination frameworks. 21 In our recent work, 22 we selected benzene-1,2,4,5-tetracarboxylic acid (H 4 BTC) to coordinate with Cu 2+ , and successfully prepared a highly crystalline Cu-MOF (denoted as HNNU-2) with excellent chemical stability, and also found its enormous variation in the proton conductivity due to the reversible single crystal-single crystal transformation. Interestingly, by introduction of a zwitterion pyridiniumolate 1,1′,1″-(2,4,6-trimethylbenzene-1,3,5-triyl)tristripyridinium-4-olate (abbreviated as TTP) as a SIA in this reaction solution, a new family of 2D-layered Cu-CPs ([Cu 2 (H 2 BTC) 2…”

“…In our recent work, 22 we selected benzene-1,2,4,5-tetracarboxylic acid (H 4 BTC) to coordinate with Cu 2+ , and successfully prepared a highly crystalline Cu-MOF (denoted as HNNU-2 ) with excellent chemical stability, and also found its enormous variation in the proton conductivity due to the reversible single crystal–single crystal transformation. Interestingly, by introduction of a zwitterion pyridiniumolate 1,1′,1′′-(2,4,6-trimethylbenzene-1,3,5-triyl)tristripyridinium-4-olate (abbreviated as TTP ) as a SIA in this reaction solution, a new family of 2D-layered Cu-CPs ([Cu 2 (H 2 BTC) 2 2− ]·4(H 3 O + )·4Cl − ·3H 2 O ( HNNU-1α ), [Cu 2 (H 2 BTC) 2 2− ]·2(H 3 O + )·2Br − ·4H 2 O ( HNNU-1β ), [Cu 2 (H 2 BTC) 2 2− ]·2(H 3 O + )·2I − ·4H 2 O ( HNNU-1γ )) were successfully constructed (Fig.…”

High Proton Conductivity in Nafion/Ni-MOF Composite Membranes Promoted by Ligand Exchange under Ambient Conditions

“…Driven by strong coordination, original metal ions dissociate from the ligands and enter the solution, while new metal ions enter the crystal lattices from the solution and coordinate with the ligands. The reciprocating shuttle movement caused by the dissociation and coordination of metal ions endows the cavity with MOF functionalization, which makes proton transfer more convenient and faster, thereby enhancing the proton conductivity of exchange products. − …”