1) Preparation of catalyst
The metal aluminum plate (thickness of 0.1mm, purity of 99.0%) was immersed in NaOH solution with a mass fraction of 20% for 3 minutes, and then immersed in a HNO3 solution with a volume fraction of 30% for 1 minute to remove the natural oxide layer on the surface of metal aluminum. The treated aluminum plate was used as the anode, the lead plate was used as the cathode, and the oxalic acid with a mass fraction of 4% was used as the electrolyte. , the Al2O3-Al carrier was made into the form of Raschig ring packing with a diameter of about 3mm, and after being water-sealed in a water bath at 80°C for 1.5h, the carrier was calcined at 350°C for 1h. The catalyst carrier was immersed in a certain concentration of Mg(NO3)2 solution, stirred at a certain temperature for a certain period of time and then left to stand for a certain period of time. After the impregnation was completed, it was dried in an oven at 125 °C for more than 8 hours. The filler-type MgO/Al2O3-Al solid base catalyst is prepared by roasting at a certain temperature for a certain period of time.
2) Acetone condensation reaction
The condensation reaction was carried out in a 250mL three-necked flask, the reaction temperature was controlled with a junction thermometer, and heated and stirred with a SZCL type digital temperature-controlled magnetic stirrer. The catalytic reaction was carried out under boiling conditions, 100 mL of raw material acetone was added, the catalyst loading was 2 g, no water agent was added, and the reaction time was 1 h. The results show that the suitable preparation conditions of the catalyst are as follows: the concentration of impregnation solution is 2.0%, the impregnation temperature is 55℃, the impregnation time is 2.0h, and the roasting temperature is 550℃ and the roasting time is 4.0h. Under this condition, the conversion of acetone was 21.08%, and the selectivity of diacetone alcohol was 100%.
