Abstract
Comparative studies on the vapor phase and liquid phase oxidation of ethylene were made with palladium chloride-active charcoal catalyst. The catalyst activity in the vapor phase reaction was higher than that in the liquid phase reaction. Acetaldehyde was obtained with high selectivity in both phases. The rate of acetaldehyde formation in the vapor phase was accelerated by the increase in steam pressure and was suppressed by the rise in the reaction temperature while the rate in the liquid phase reaction was accelerated by the rise in the reaction temperature. Aqueous hydrogen chloride solution of about 0.1N was effective as a reaction medium to keep the catalyst activity constant. Contrary to the vapor phase reaction the rate in the liquid phase reaction decreased with the increase in partial pressure of oxygen.
