Selective hydrogenation of crotonaldehyde in liquid-phase over Au/Mg2AlO hydrotalcite catalysts

The liquid-phase selective hydrogenation of crotonaldehyde to crotyl alcohol over Au supported on a solid base of Mg2AlO-hydrotalcite (Mg/Al = 2) was investigated. The 2% Au/Mg2AlO catalysts were prepared using a modified deposition precipitation method without adjusting the pH of the initial HAuCl4 solution. The influence of the calcination temperatures of the Mg2AlO support and of the 2% Au/Mg2AlO catalyst, and the effects of the reaction medium (solvent), temperature, pressure and concentration were studied. The promoter, Fe, Mo or W, was co-deposited with Au on Mg2AlO to maximize the yield of crotyl alcohol. 2% Au/Mg2AlO was compared with Au supported on FeOOH, Fe2O3, CeO2, TiO2 and Al2O3. The correlation between the gold states (Au3+/Au0) and the activity and selectivity of crotyl alcohol was extensively examined.

Gold dispersed on the solid base of Mg2AlO hydrotalcite could selectively hydrogenate crotonaldehyde (UAL) to crotyl alcohol (UOL). A high selectivity value of UOL, about 62%, was obtained near complete conversion and the UOL was not successively reduced to 1-butanol (SOL). The correlation between the gold states (Au3+/Au0) and the activity and selectivity was extensively examined.Figure optionsDownload high-quality image (51 K)Download as PowerPoint slide