Hourglass-Type Polyoxometalate-Based Crystalline Material as an Efficient Proton-Conducting Solid Electrolyte

Abstract

Proton exchange membrane fuel cells are limited because they are limited to working temperatures and are susceptible to damage by dramatic electrochemical environments such as hydrogen peroxide/radicals. It is necessary to develop new proton-conducting materials that are water-stable and can operate at high temperatures. The hourglass reduced molybdophosphate-based compound (H2bimb)3[Zn3(H6P4Mo6O31)2] (bimb = 1,4-bis[(1H-imidazol-1-yl)methyl]benzene) was designed and synthesized under solvothermal conditions. Single-crystal X-ray diffraction analyses demonstrated noticeably that CUST-571 was composed of an hourglass {Zn[P4Mo6]2} structure, which consisted of two fully reduced half-units {P4Mo6}. It was found that CUST-571 possessed an excellent proton conductivity of 4.54 × 10–3 S cm–1 at 85 °C and 98% RH (relative humidity). In addition, CUST-571 is capable of an excellent catalytic decomposition of H2O2, which is beneficial to increase the life of fuel cells. On the basis of the aforementioned results, CUST-571 may be a promising proton-conducting polyoxometalate hybrid material in the future.

Solid-state supercapacitors based on polyoxometalate-based crystalline materials modified with polyaniline

“…The X-Ray photoelectron spectroscopy of complexes exhibits two peaks at 231.58 eV, 234.78 eV, and 232.43 eV, 235.8 eV, which indicates that Mo atoms are in the reduced state. The characteristic peaks of 782.28 eV, 786.78 eV, 797.88 eV, and 800.28 eV correspond to Co 2+ , and 645.13 eV, 657.13 eV correspond to Mn 2+ , respectively 45,46 (Fig. S4 †).…”

Application of Ionic Hydrogen-Bonded Organic Framework Materials in Hybrid Proton Exchange Membranes

“…Therefore, it is very urgent for us to find some cheap materials that can exhibit excellent proton conductivity. Solid-state proton-conducting materials − play an extremely important role in various electrochemical devices. In recent years, great progress has been made in the study of proton conductivity of solid crystalline PEM materials.…”

Two new manganese-based phosphomolybdate compounds as electrochemical sensors for the highly sensitive trace determination of heavy metal Cr(vi) ions

“…30–32 All Mo atoms in {P 4 Mo 6 } have high-reduction states, showing obvious redox properties in the electrochemical process. 28,33–36 Recently, {P 4 Mo 6 }-based compounds have been widely used in the field of electrochemistry with good results, such as electrocatalytic reduction of Cr( vi ), 6,37,38 electrocatalytic hydrogen, 39,40 oxygen production, 41 battery, 42 and proton conduction. 34,43,44 Han and his co-workers used electrochemical sensing technology to detect Cr( vi ) based on {P 4 Mo 6 }-containing compounds.…”

“…28,33–36 Recently, {P 4 Mo 6 }-based compounds have been widely used in the field of electrochemistry with good results, such as electrocatalytic reduction of Cr( vi ), 6,37,38 electrocatalytic hydrogen, 39,40 oxygen production, 41 battery, 42 and proton conduction. 34,43,44 Han and his co-workers used electrochemical sensing technology to detect Cr( vi ) based on {P 4 Mo 6 }-containing compounds. The results show that these two compounds have lower LODs and good selectivity and stability.…”

“…[30][31][32] All Mo atoms in {P 4 Mo 6 } have high-reduction states, showing obvious redox properties in the electrochemical process. 28,[33][34][35][36] Recently, {P 4 Mo 6 }based compounds have been widely used in the field of electrochemistry with good results, such as electrocatalytic reduction of Cr(VI), 6,37,38 electrocatalytic hydrogen, 39,40 oxygen production, 41 battery, 42 and proton conduction. 34,43,44…”