Structural features of proton-conducting metal organic and covalent organic frameworks

Abstract

Proton conducting materials have been gaining significant attention due to their applicability as solid electrolytes in proton exchange membrane fuel cells (PEMFCs). The confined architectural design and open space in...

The Role of Superadsorbent Polymers on Covalent Organic Frameworks‐Based Solid Electrolytes: Investigation of the Ionic Conductivity and Relaxation

“…[31] On the other hand, at high temperatures (60-80 °C) E a reaches a value of 0.63 eV, which is coherent with a vehicle mechanism, meaning that there is enough energy also for the movement of proton carriers through the network. [10] Being the high crystallinity one of the greatest advantages in employing COFs as proton conductors, [12] we propose for the first time, to the best of our knowledge, an elucidation of the structure at variable RH by XRD, in order to gain greater insight into the proton conduction mechanism. Figure 4 shows that the diffraction from the (100) plane appears at 2.45° for both the pristine TPDA-PDA and TPDA-PDA/150 µL PANa.…”

“…[ 8 ] The great variability of the properties is directly translated into a wide range of applications, spanning from adsorption of contaminants and molecular sieving to catalysis, sensing, energy storage, and proton conduction. [ 1,9,10 ] Although pristine COFs are not particularly appealing for applications as proton conductors due to the difficult incorporation of proton‐donating functionalities in their backbone, they can be combined with several protonic species (phosphoric acid, phytic acid, or N‐heterocycles) yielding materials with enhanced proton conducting properties. The first example of such an approach has been reported in 2014 by Chandra et al., who demonstrated that an azo‐functionalized COF can achieve σ of 9.9 × 10 −4 S cm −1 when loaded with phosphoric acid, while the pristine COF was not intrinsically a proton conductor.…”

A Cr(iii) supramolecular network composite membrane with high water stability and proton conductivity

“…5 The commercially Nafion membranes have superior proton conductivity, but they require a complicated manufacturing process and high manufacturing cost. 6 In addition, it is necessary for enough humidification at elevated temperatures to achieve high proton conductivity, 7 which needs to power the humidification put extra cost and a low tolerance for fuel impurities (CO and S). 8 These remain as a scientific drawback of Nafion.…”

Enhancing Proton Conductivity of Nafion Membrane by Incorporating Porous Tb-Metal–Organic Framework Modified with Nitro Groups

“…Metal–organic frameworks (MOFs) have attracted much attention because of their extensive applications. − Especially, more and more researchers are interested in MOFs as proton conductors in recent years. − In order to enhance the σ H+ of MOFs, researchers usually fill MOF pores with proton carriers, such as NH 4 + or H 2 O, as guest molecules, expecting to form rich hydrogen bond networks between guest molecules and host framework, providing pathways for proton conduction. The second strategy commonly used to improve MOF proton conductivities is to use substituents, such as −SO 3 H and −COOH, to modify rigid ligands, expecting to form hydrophilic channels and facilitate proton transfer .…”