Synthesis and properties of magnetic solid acid catalyst S2O82-/ZrO2-Mn-Zn ferrite.

Mn1-xZnxFe2O4 (Mn-Zn ferrite) and S2O82-/ZrO2-Mn1-xZnxFe2O4 were synthesised by soaking-calcination method and chemical coprecipitation approach, respectively. The optimal synthesis conditions of S2O82-/ZrO2- Mn-Zn ferrite were as follows, 25% mass ratio of Mn-Zn ferrite to ZrO2, (NH4)2S2O8 solution of 0.4 mol/L and the calcination temperature of 600℃. The as-synthesised composite with the nano size of the particles possessed excellent catalytic activity for esterification reaction under 78℃. The largest yield of ethyl acetate using the as-prepared magnetic solid acid catalyst was 78.6%, while the yield was only 66.7% using (NH4)2S2O8 catalyst in the esterification reaction. The recovery ratio of the magnetic catalyst S2O82-/ZrO2- Mn-Zn ferrite was still more than 80% after 3rd cycles, which facilitated to promote the scale application of magnetic solid acid catalyst. [ABSTRACT FROM AUTHOR]