Tetraethylammonium hydroxide is widely used as a phase transfer catalyst in organic synthesis, facilitating the movement of reactants between immiscible phases to enhance reaction rates and yields. It is also employed in the preparation of quaternary ammonium compounds, which are essential in various industrial applications. In analytical chemistry, it serves as an ion-pairing agent in chromatography to improve the separation of complex mixtures. Additionally, it is utilized in the production of specialty chemicals and as a reagent in the synthesis of pharmaceuticals, where its strong basicity is advantageous. In electrochemistry, it acts as an electrolyte additive to optimize the performance of batteries and other electrochemical systems.