Metal Organic Frameworks Modified Proton Exchange Membranes for Fuel Cells

Proton exchange membrane fuel cells (PEMFCs) have received considerable interest due to their low operating temperature and high energy conversion rate. However, their practical implement suffers from significant performance challenge. In particular, proton exchange membrane (PEM) as the core component of PEMFCs, have shown a strong correlation between its properties (e.g., proton conductivity, dimensional stability) and the performance of fuel cells. Metal-organic frameworks (MOFs) as porous inorganic-organic hybrid materials have attracted extensive attention in gas storage, gas separation and reaction catalysis. Recently, the MOFs-modified PEMs have shown outstanding performance, which have great merit in commercial application. This manuscript presents an overview of the recent progress in the modification of PEMs with MOFs, with a special focus on the modification mechanism of MOFs on the properties of composite membranes. The characteristics of different types of MOFs in modified application were summarized.

Crystal structure of catena-poly[diaqua-bis(μ2-5,5′-(1H-imidazole-4,5-diyl)bis(tetrazol-2-ido)-κ4 N,N′:N′′,N′′′)magnesium], C10H8N20O2Mg

C10H8N20O2Mg, orthorhombic, Pnma (no. 62), a = 12.4217(8) Å, b = 7.3444(6) Å, c = 10.6063(7) Å, V = 967.61(12) Å3, Z = 2, Rgt (F) = 0.0411, wR ref(F 2) = 0.1147, T = 293(2) K.

A dual-functional MOF for high proton conduction and sensitive detection of ascorbic acid

A new Eu-MOF detects AA with turn off fluorescence and the proton conductivity of the Im@Eu-MOF is ten times higher than that of the En-MOF.

Synthesis and magnetic properties of two Mn-based coordination polymers constructed by a mixed-ligand strategy

Two Mn(ii) CPs have been synthesized by mixed-ligand strategy and measured for their magnetic properties. Moreover, analysis of the magnetic structure–effect relationship indicates that 1 and 2 have different Mn chains of magnetic interactions.

Preparation and Analyses of the Multifunctional Properties of 2D and 3D MOFs Constructed from Copper(I) Halides and Hexamethylenetetramine

In this article, two two-dimensional and three-dimensional metal-organic frameworks are synthesized by the self-assembly of copper(I) halide and the hexamethylenetetramine (hmt) ligand. Compound 1 is a two-dimensional metal-organic framework composed of a pyramidal Cu₄I₅ cluster and hexamethylenetetramine, in which hmt-bridged Cu clusters form a two-dimensional (4,4)-connected net with a point symbol of (4⁴·6²) (4⁴·6²). Compound 2 is a homochiral three-dimensional metal-organic framework material generated through an unusual spontaneous crystallization from achiral precursors. The two compounds were characterized by a series of analyses such as infrared spectroscopy, elemental analysis, circular dichroism spectroscopy, and powder X-ray diffraction. Both of them exhibit unexpected stability under a wide range of conditions of acid and base. In addition, the fluorescence intensity changes regularly under acid-base conditions. Stokes shift shows a good linear relationship with -log [H⁺], which makes them become promising acid-base sensors. Compounds 1 and 2 also display selective adsorption and a significant degradation effect on the organic dye methylene blue. In addition, the fluorescence study indicated that compound 2 could be used as a sensor to detect Cr³⁺.

Rational synthesis, crystal structure, and sensing and adsorption properties of luminescent metal–organic frameworks

Five novel Cd(ii) metal–organic frameworks (Cd-MOFs) were synthesized employing a rational design approach under solvothermal conditions. The luminescence sensing and the targeted dye adsorption properties of the MOFs 1–5 are investigated.

High proton conductivity in a nickel(ii) complex and its hybrid membrane

A novel 2D nickel(ii) complex (1) has been successfully synthesized using a 2,2′-bipyridyl, polycarboxylsulfonate ligand H₄SBTC and Ni²⁺ ions. Owing to the presence of abundant water molecules, hydrogen bond networks and other protons, 1 and its hybrid membranes demonstrate high proton conductivity.

A new europium metal–organic framework with both high proton conductivity and highly sensitive detection of ascorbic acid

The highest proton conductivity of the new Eu-MOF reaches up to 1.0 × 10⁻⁴ S cm⁻¹. Furthermore, it is an excellent luminescence-based sensor for detection of ascorbic acid (AA) in aqueous solutions.