From molecule to material: Mg₂Sn as hydrogenation catalyst

The liquid-phase hydrogenation of citral has been studied for the first time over an ionogenic Zintl phase, Mg2Sn. By using this unsupported alloy, citral conversion was 20% at 448 K and the product mixture was mainly comprised of geraniol, nerol, citronellal and citronellol. The product ratio of the formation of unsaturated allyl-type alcohols to the formation of citronellal + citronellol is similar to that obtained with the unsupported alloy Ru3Sn7 and a silica supported Ru–Sn catalyst. The results clearly indicate that the polar character of active sites is a prerequisite for the chemisorption of the polar C=O group and, thus, must be a key factor in controlling the selectivity of the hydrogenation of α,β-unsaturated aldehydes