关键词: 氧化镁, 氧化铝, 催化, 机械混合法, 合成

Abstract: The catalysts with different ratio of Mg and Al were prepared by machine mixing method with MgO and Al₂O₃ as raw materials, the activity of catalysts was evaluated in a fixed bed reactor with the synthesis of isophorone by gas acetone as probe reaction, and the catalysts were characterized by XRD, XPS and TPD. The results showed that the activity of catalysts prepared by machine mixing method was high, the ratio of Mg and Al had little effect on the crystalline structure and surface acid-base strength, but had significant effect on the surface acid-base amount of catalysts. When the ratio of Mg and Al was 1:1.8 to 1:1, the surface acid-base amount of catalysts was higher, so the activity of catalysts was higher. When the ratio of Mg and Al was 1:1, the conversion of acetone and selectivity of isophorone were 11.5% and 62.8% respectively. By adjusting catalyst loading amount, the residence time of reactants was effectively prolong, the conversion of acetone was increased. Under the reaction conditions of atmospheric pressure, reaction temperature 300℃, liquid space velocity 0.67h^-1, the conversion of acetone and the selectivity of isophorone were 21.0% and 73.0% respectively.

Key words: magnesia(MgO), oxidation aluminium(Al₂O₃), catalysis, machine mixing method, synthesis