Fe–Zn-doped S2O8 2−/ZrO2–Al2O3 (SZA) catalysts were synthesized and characterized by using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) analysis, Fourier transform infrared (FT–IR) measurements, hydrogen temperature-programmed reduction (H2–TPR), and pyridine infrared (Py–IR) measurements. The effects of Fe and Zn on the structure and isomerization performance of SZA were studied using n-pentane as a probe reaction. Results showed that all of the samples show the pure peaks of tetragonal ZrO2. The addition of Zn can improve the redox performance of the catalysts, while Fe can lead to a better dispersion of sulfate ions on the surface of the catalysts. As a result, an improvement in the redox performance of the Zn–Fe–SZA catalyst was observed. The Zn or Fe can increase mainly Lewis acidity of the SZA, and the total acidity of samples decrease in the following order: Zn–Fe–SZA > Zn–SZA > Fe–SZA > SZA. The Fe–Zn–SZA catalyst exhibits the best catalytic activity for n-pentane isomerization. The isopentane yield of the Zn–Fe–SZA catalyst reaches 67.2 % at 443 K, which is an increase of 44.2 % when compared with that found for SZA at its optimum temperature of 573 K.