Hydrogenation of 2-ethyl-hexen-2-al on Ni/Al2O3 catalysts

Abstract

This work describes the hydrogenation of 2-ethyl-hexen-2-al in a slurry bed reactor in liquid phase on Ni/Al2O3 catalysts (4.4-17.0% wt Ni). XRD, DRS and TPR results showed the presence of superficial Ni 2+ species in octahedral (surface Ni oxide) and tetrahedral coordination (spinel-type phase) in the subsurface of the support. Nickel oxide crystallites were found in samples with Ni content above 7.3%, either in tetrahedral or octahedral coordination. The highest selectivity for 2-ethyl-hexanal was obtained with the catalysts containing 7.3% wt Ni. The turnover frequency (TOF) was independent on the Ni concentration, suggesting that this hydrogenation reaction is structure insensitive.