| Abstract: | The kinetics of the consecutive hydrogenation reactions 2-ethyl-hexenal → 2-ethyl-hexanal → 2-ethyl-hexanol were studied in the liquid phase in presence of commercial Ni, Pd and Ni-S catalysts. The Pd and Ni-S catalysts were extremely selective with respect to the formation of 2-ethyl-hexanal, while the full reaction sequence was readily catalyzed by nickel. A Langmuir-Hinshelwood model with dissociative hydrogen adsorption was found to be the most probable model, for all three catalysts. The proposal of dissociative hydrogen adsorption of the Ni-S catalyst was supported by an independent gas-phase experiment, using the H2/D2 exchange reaction as a model reaction for the hydrogen àdsorption process. |
