The liquid-phase selective hydrogenation of crotonaldehyde to crotyl alcohol over Au supported on a solid base of Mg(2)AlO-hydrotalcite (Mg/Al = 2) was investigated. The 2% Au/Mg(2)AlO catalysts were prepared using a modified deposition precipitation method without adjusting the pH of the initial HAuCl(4) solution. The influence of the calcination temperatures of the Mg(2)AlO support and of the 2% Au/Mg(2)AlO catalyst, and the effects of the reaction medium (solvent), temperature, pressure and concentration were studied. The promoter, Fe, Moor W, was co-deposited with Au on Mg(2)AlO to maximize the yield of crotyl alcohol. 2% Au/Mg(2)AlO was compared with Au supported on FeOOH, Fe(2)O(3), CeO(2),TiO(2) and Al(2)O(3). The correlation between the gold states (Au(3+)/Au(0)) and the activity and selectivity of crotyl alcohol was extensively examined. (C) 2010 Elsevier B.V. All rights reserved.
