Liquid phase hydrogenation of crotonaldehyde over Sn-promoted amorphous Co–B catalysts

Abstract

Abstract The promoting effect of tin (Sn) on the liquid phase hydrogenation of crotonaldehyde over amorphous Co–B catalyst has been investigated. SnCl 2 or SnCl 4 was introduced to the reactant before hydrogenation or incorporated to the Co–B catalyst during the reduction of CoCl 2 by potassium borohydride. The overall activity of the Co–B catalyst was suppressed upon the addition of the tin salts in the reactant. However, an appropriate amount of either tin salt remarkably improved the reactivity towards the CO bond, thus leading to a higher selectivity and yield of crotyl alcohol. On the other hand, incorporation of tin to the catalyst by co-reduction was mainly against the formation of crotyl alcohol. SnCl 2 caused a sharp drop of the reactivity towards the CO bond rather than the CC bond. Although SnCl 4 increased both the reactivities of the CO and CC bonds, the former increased to a less extent than the latter. Their different catalytic behavior was tentatively interpreted on the basis of XPS measurements.