Synthesis and characterization of S₂O₈^2-/ZrO₂ SrFe₁₂O₁₉ strontium magnetic solid acid catalyst

The magnetic solid acid catalyst(S₂O₈^2-/ZrO₂-SrFe₁₂O₁₉) was prepared by strontium ferrites(SrFe₁₂O₁₉) particle carrying with solid acid, which exhibited excellent magnetic properties as a magnetic matrix. The surface properties and catalytic performance of the magnetic catalyst were analyzed by means of XRD, nitrogen adsorption-desorption (BET), vibrating sample magnetometer (VSM), FTIR. The results show that the introduction of SrFe₁₂O₁₉ can increase thermal stability of the metastable tetragonal type t-ZrO₂. The saturated magnetization (M_s) is about 30.0 emu穏^-1, and the coercive force is greater than 3900 G, which is good for the magnetic separation and reuse. The specific surface area of solid acid is 16.0 m²穏^-1 and the average pore size is 8.16 nm, certifying that the solid acid catalyst is a mesoporous magnetic material. The test for transesterification by tallow oil with methanol as probe reaction shows that the solid acid becomes an effective catalyst in a relatively short time.