Influence of the preparation method on the structural and surface properties of various magnesium oxides and their catalytic activity in the Meerwein-Ponndorf-Verley reaction

The Meerwein-Ponndorf-Verley (MPV) reaction of cyclohexanone with isopropyl alcohol, which yields cyclohexanol, was studied by using basic catalysts consisting of magnesium oxide. The oxides were prepared using various synthetic procedures including calcination of commercially available magnesium hydroxide and carbonate, calcination of magnesium hydroxides obtained from magnesium nitrate and sulphate, the sol-gel technique and precipitation by decomposition of urea. The solids thus obtained were characterized structurally by X-ray diffraction spectroscopy and their surface properties determined using gas adsorption measurements (of nitrogen for textural properties and carbon dioxide for basic properties). Based on the results, the most active catalyst was the solid prepared by rehydration and subsequent calcination of a magnesium oxide that was previously obtained from commercially available magnesium hydroxide. (C) 2003 Elsevier Science B.V. All rights reserved.