Sulfated zirconia (SZ) and a solid super acid catalyst cerium-supported SZ (Ce/SZ) were prepared using the sol–gel method in an acidic medium. The prepared catalyst was modified through the addition of different amounts of cerous chloride heptahydrate. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction were used to detect the physiochemical properties of the prepared catalysts. The strength and number of acid sites were detected by potentiometric titration and Fourier transform infrared spectroscopy of the pyridine adsorbed on the catalysts. The catalytic activity of the prepared catalysts was examined by coumarin synthesis. The reaction was conducted by consuming resorcinol and ethyl acetoacetate in the molar ratio of 1:2. In addition, the activity of the prepared catalysts was examined by Fe removal, and a 3, 4-dihydropyrimdone reaction which was performed by consuming urea, benzaldehyde, and ethyl acetoacetate in the molar ratio of 1.5:1:1.