The Catalytic Synthesis of Higher Ketones from 2-Propanol

抄録

The catalytic activities of Cu-Cr₂O₃-ZnO and Cu-ZnO systems for vapor phase condensation of 2-propanol were studied. The reaction was carried out by a flow method under the conditions of atmospheric pressure and LHSV=2hr^-1. The surface area and grain size of metallic copper on the used catalysts were measured by carbon monoxide adsorption and X-ray diffraction methods, respectively.
As the reaction products, higher ketones such as 4-methyl-2-pentanone (MIBK), 2, 6-dimethyl-4-heptanone (DIBK) and 2, 6, 8-trimethyl-4-nonanone (TMN) were obtained in high yield at about 250°C in addition to acetone which was thought to be an intermediate compound to above ketones.
The catalytic activity for condensation was considered to be caused by the existence of metallic copper on the catalysts and therefore, a higher total yield of condensation products was obtained by using a catalyst with larger surface area of copper on it.
Catalysts which contain larger amount of copper, have larger grain size of metallic copper, but no exact correlation between grain size of copper and the catalyst activity was found.
When 2-propanol was passed over the three-component catalyst with atomic ratio of Cu:Cr:Zn=0.5:1:1 at 255°C the highest activity for condensation was obtained, namely, yields of MIBK, DIBK and TMN were 29%, 27% and 13% (based on 2-propanol fed), respectively.