1984 Volume 10 Issue 4 Pages 439-445
Partial oxidation of propylene by an aluminum tube wall catalytic reactor was carried out. The catalyst used was copper metal deposited on the inner wall of the reactor, and under various conditions the catalyst activities at the initial stage and after long continuous reaction time were measured and analyzed. Though the catalyst activity at the initial stage could be nearly constant, it changed slowly and approached definite constant values.
At this final stage the effects of reaction conditions on catalytic activity were studied experimentally, and it was found that the catalyst showed two different acrolein production rates depending on the partial pressures of propylene and oxygen; that is, it had high- and low-activity regions. The former was found to be about 100 times higher than the latter, and by analysis of the reaction conditions the difference was assumed to be due to the difference in oxidative state of the copper catalyst.
To prove these characteristics of the catalyst, its weight change under these reaction conditions was measured by a temperature gravimetry method.
The results showed that in the state of high acrolein activity the total weight of the catalyst was nearly equal to that of the original copper, and in the low-activity state the weight increase from the original copper corresponded to its oxide state.
These distinct characteristics of acrolein production activity were observed only for the catalyst after long continuous reaction time.