The synthesis, characterization, and application of a NiO-PO4/SiO2 catalyst for ethanol dehydration to diethyl ether were successfully conducted. The sol-gel method utilized TEOS as the silica source, NaHCO3 as a template, and different phosphoric acid concentrations (1, 2, and 3 M). Calcination occurred at temperatures of 400, 500, and 600 °C. The catalyst with the highest acidity underwent impregnation with 1, 2, and 3% (w/w) nickel precursor proceeded by calcination with N2 gas. Characterization techniques included FTIR, XRD, SEM-EDX, and AAS. The application of SP 2-NiO 3% catalyst as the catalyst with the highest acidity demonstrated significant activity and selectivity in diethyl ether production at 175, 200, and 225 °C temperatures, yielding 88% conversion and 5.07% diethyl ether selectivity at its optimum temperature of 225 °C.