Executive Summary : | Proton conducting materials are crucial for fuel cells, gas sensors, and electrochemical devices. Researchers worldwide are exploring inorganic-organic hybrid materials like metal organic frameworks (MOFs) and coordination polymers (CPs) for their proton conducting properties. Proton transfer from an acid to a base promotes proton conduction in the solid state, and polyoxometalates (POMs) are an important class of proton conductive materials due to their high proton carrier density and increased mobility. However, POM-based salts have low structural stability due to high solubility. This research proposal explores various approaches to minimize these drawbacks and uses POMs as proton conducting materials. One promising approach is to hybridize POMs with appropriate organic counter cations, resulting in POM-based insoluble materials containing mobile protons. POM-based water-insoluble ion-pair compounds can be classified into four groups: 1) POM materials with inorganic cations (coordination polymers, extended structure), 2) POM materials with organic cations (protonated organic molecules), 3) POM-organic polymers, and 4) Host-guest materials (POMs incorporated into MOFs' and COFs' internal void spaces). The proposed POM-based water-insoluble proton-rich materials will be synthesized and characterized, subjected to electrochemical impedance spectroscopy (EIS) to obtain proton conductivity values in the solid state. After synthesizing POM-based proton conductive solid electrolytes, detailed kinetic- and thermodynamic studies will be conducted to understand the underlying chemistry of the synthesized materials. Finally, water-insoluble solid POM electrolytes will be used as nano-fillers in organic polymers to fabricate inorganic-organic membranes for practical fuel cell applications. |