Proton Conductivity in {Mo₇₂Fe₃₀}‐Type Keplerate

Abstract

Proton conductivity studies for Keplerate cluster containing compound, [Mo 72 Fe 30 O 252 (CH 3 COO) 12 {Mo 2 O 7 (H 2 O)} 2 {H 2 Mo 2 O 8 (H 2 O)} (H 2 O) 91 ] • 150H 2 O (1) have been performed. Compound 1 exhibits a conductivity value of 1.85 × 10 À 3 S cm À 1 under humidified (RH = 50 %) and low temperature (< 330 K) conditions. The water molecules, present in this system along with deprotonated (iron coordinated) water molecules of compound 1, are responsible for the movement of the protons within its discrete clusters in the relevant crystals, following Grotthuss mechanism.

Unravelling the Bi‐Functional Electrocatalytic Properties of {Mo72Fe30} Polyoxometalate Nanostructures for Overall Water Splitting Using Scanning Electrochemical Microscope and Electrochemical Gating Methods

“…[ 27 ] In these, Keplerate‐type polyoxometalate {Mo 72 Fe 30 } clusters possess distinct properties such as visible‐light‐driven photocatalyst, an anode for Li‐ion batteries, the catalyst for organic synthesis, reversible redox mediators for the synthesis of metal nanoparticles, targeted drug delivery agent, and hybrid materials, proton conductivity, electrocatalyst for HER, and excellent guest/host chemistry. [ 27 , 31 , 32 , 33 , 34 , 35 ] To date, the electrocatalytic properties of {Mo 72 Fe 30 } POM for overall water splitting are not yet studied; however, it is expected that they can possess excellent electrocatalytic activity that is due to the presence of Mo and Fe atoms in their highest oxidation state. [ 36 , 37 ] In this work, we have demonstrated the better electrochemical catalytic properties of {Mo 72 Fe 30 } POM as a universal catalyst for HER and OER applications using standard electrochemical studies.…”