Tetrabutylammonium nitrate is widely used as a phase transfer catalyst in organic synthesis, facilitating the transfer of reactants between immiscible phases, particularly in reactions like nucleophilic substitutions and alkylations. It is also employed in electrochemical studies as an electrolyte additive to enhance conductivity and stability in various battery systems. Additionally, it serves as a reagent in the preparation of ionic liquids and in the synthesis of organic compounds where its nitrate ion can act as a mild oxidizing agent. Its role in analytical chemistry includes its use as a counterion in ion-pair chromatography for the separation and analysis of complex mixtures.