Supported Cobalt Catalysts for Acceptorless Alcohol Dehydrogenation
Kamila Kaźmierczak, Catherine Pinel, S. Loridant, Michèle Besson, Carine Michel, Noémie Perret
Abstract
Abstract The acceptor‐less dehydrogenation of 2‐octanol was tested over cobalt supported on Al 2 O 3 , C, ZnO, ZrO 2 and various TiO 2 substrates. The catalysts were characterized by ICP, XRD and TGA‐H 2 . For Co/TiO 2 P25, the effects of passivation, aging (storage at room temperature), and in situ activation under H 2 were investigated. The catalysts must be tested shortly after synthesis in order to prevent deactivation. Cobalt supported on TiO 2 P25 was the most active and 69 % yield of 2‐octanone was obtained, using decane as a solvent. Selectivities for 2‐octanone were observed in the range of 90 % to 99.9 %. Small amounts of C16 compounds were also formed due to aldol condensation/dehydration reactions. The catalysts exhibited higher conversion in the dehydrogenation of secondary alcohols (65‐69 %), in comparison to primary alcohols (2–10 %). The dehydrogenation of 1,2‐octanediol led to 1‐hydroxy‐2‐octanone, with a selectivity of 90 % and 69 % for Co/TiO 2 P25 and Co/TiO 2 P90, respectively.