An apparatus is described to measure volumetrically the amount of gas adsorbed by a catalyst a t constant pressure and at exposure times as short as 0.1 min. The volumes of oxygen adsorbed by a technical silver catalyst a t pressures of 200, 400, and 700 mm. and in the temperature range of 180" to 300" C. have been measured. Surface area determinations of 0.33 t o 0.38 sq. meter per gm. of catalyst by physical adsorption and chemisorption methods show that each silver atom of the surface is associated with approximately one osygen adatom a t a monolayer coverage. The initial rate of adsorption of oxygen is directly proportional to its pressure. Observed transitions in the oxygen adsorption rates indicate that more than one type of oxygen comples occurs on the catalyst surface. The Elovich equatioli provides the best approximation of the adsorption rate data but is of limited applicability in interpretation of the ~iiechanism of adsorptio~i. 1:alues of 22-29 Iccal./~ilole and 17-25 lical./mole have been calculated for the apparent activation energy and isosteric heat of adsorption respectively.

An improved method of preparing polymethylene, (CH2)n, by the decomposition of diazomethane is described. A new polymer, polyethylidene, (CH3∙CH)n, has been obtained from diazoethane by the same reaction. Diazomethane-d2 is reported for the first time. A new deuterated polymer, (CD2)n, obtained by the decomposition of diazomethane-d2 has been synthesized.

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The pyrolysis of the lower paraffins in externally heated quartz tubes has been studied under conditions of streamline and turbulent flow. It has been found possible to produce a high degree of turbulence in the flow of paraffin gases through tubes heated to a high temperature. It has been shown that when the pyrolysis is carried out under conditions of turbulent flow the yields of olefines obtained at a given temperature are greatly increased over those obtained in an open tube. It is further shown that under conditions of turbulent flow higher rates of conversion of the lower paraffins to olefines are possible since the temperatures at which side reactions begin to be noticeable are considerably higher under the above conditions than when the gas flow is streamline.

The catalytic oxidation of ethylene to ethylene oxide was investigated in flow experiments over silver catalysts at atmospheric pressure between 260° and 350 °C. Calcium oxalate and stannous oxide were used as catalyst promoters. Close temperature control was provided by mounting the catalyst on a silver support. At 270 °C. the selectivity increased from about 25%, with ethylene in large excess, to about 55%, with oxygen in large excess. With air constant and in large excess, the over-all reaction rate was found to be proportional to the square root of the ethylene concentration. With ethylene constant and in large excess, the reaction rate was found to be roughly proportional to the oxygen concentration. The presence of methane, ethane, or propane promoted the complete oxidation of ethylene to carbon dioxide and water. In the absence of paraffins the addition of traces of ethylene dichloride only served to poison the catalyst.