| In this paper, the series of Magnesium-Aluminum oxides catalysts with different Mg/Al ratios were prepared by coprecipitation and wet-mixing-kneading methods, and their properties were characterized by XRD, BET, EDS and FT-IR methods. The acetone vapor-phase condensation reaction on Mg-Al catalysts were carried out on fixed-bed. The results show that the crystalline structure of hydrotalcites is the most complete when the Mg/Al ratio is 3, and the derivative LDO-3 of this hydrotalcite only has the characteristic diffraction of MgO. And also it has the biggest specific surface area, the smallest acidic density, the weakest acidity and the largest ratio of basic density to acidic density. The activity evaluation shows that LDO -3 has the best catalytic activity, with the conversion of acetone 36.09wt%, the selectivity of isophorone 67.34wt%. The physicochemical properties of mixing-kneading catalysts change with the ratio of Mg/Al. The bigger of the ratio of Mg/Al, the more distinct of the characteristic diffraction of MgO, and also the smaller specific surface area and the smaller acidic density. But KD-1.5 catalyst has the highest basic density. The activity evaluation shows that KD-1.5 has the best catalytic activity, with the conversion of acetone 22.84wt%, the selectivity of isophorone 50.72 wt%. Comparing LDO -3 catalyst and KD-1.5 catalyst in the side of physicochemical properties, Mg/Al ratio and catalytic performance, LDO-3 catalyst has the larger ratio of Mg/Al, the higher basic density and the larger ratio of basic density to acidic density. Meanwhile, KD-1.5 has the higher acidic density. The activity evaluation shows that LDO -3 catalyst has a better catalytic activity and a better selectivity of IP. The forming of LDO-3 is explored by coprecipitation-kneading method. The results shows that forming catalyst, LDO-3-10 (containing 10%γ-Al2O3)has the similar catalytic activity as LDO-3 catalyst and it has a better stability.
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