| Popis: |
The adsorption of butene-1, isobutene, methylvinylketone, and methylacrolein on Cu 2 O, and that of butene-1 and isobutene on CuO have been investigated by infrared spectroscopy. It has been shown that the surface compounds formed in the chemisorption of butene-1 and isobutene on Cu 2 O are of the same nature. It has been found that under similar experimental conditions the adsorption of the two main products of butene-1 and isobutene partial oxidation, methylvinylketone and methylacrolein, is essentially different. This difference lies in the fact that methylvinylketone adsorbs on the catalyst mainly irreversibly as surface carbonate compounds, while methylacrolein adsorbs largely reversibly. This difference is considered to be one of the reasons which causes the different selectivity of Cu 2 O with regard to the oxidation of butenes. On CuO, both butenes are chemisorbed in the form of carbonatecarboxylate compounds of the same composition. Data on the oxidation of C 3 -C 5 olefins and those on their chemisorption on copper catalysts have been compared. |
