MAZ catalysts were prepared by a co-precipitation method. The catalysts with different Mg/Al/Zr molar ratios (3:1:1, 2:1:1, and 1:1:1 molar ratio) were prepared by
co-precipitation
at constant pH of 10.
The calculated amounts of Mg(NO3)2·6H2O, Al(NO3)3·9H2O, and ZrO(NO3)2·H2O were dissolved in distilled water and allowed to precipitate using aqueous solution of KOH and K2CO3 at a constant pH of 10.
After
aging
for an adequate time of 18 h at 80 °C the solid was filtered off and washed with excess water to remove alkali ions. Thus obtained solid was dried at 120 °C in an oven overnight.
These hydrated samples were calcined in air at 450 °C for 4 h.
Some of the catalysts are also calcined at a temperature of 450–750 °C.
These catalysts are designated as MAZ-111, 211, 311, where the alphabetical represent the metal ion and the numbers represents their molar ratios respectively