Platinized silica gel

Hydrogen bromide gas may be produced by combustion of hydrogen in bromine vapor at 37.5°C using a catalyst such as platinized asbestos or platinized silica gel. Unreacted free bromine is removed from the product by passing the gaseous product mixture over hot activated charcoal. Hydrogen bromide formed may be absorbed in water to obtain the acid or may be cooled and liquefied for shipment in cylinders. 

Apparatus. A pyrex tube D, 50 cm. in length and 4 cm. in diameter (Fig. 29), is filled with approximately 300 g. of platinized silica gel packed at each end with a plug of glass wool. The catalyst tube is wrapped with asbestos paper and placed in the electric furnace E. The tube is drawn down at each end, and a 200-ml. distilling flask B... 

The Davison Chemical Co., Silica-Gel Division, Baltimore, Md. Editor s Note Platinized asbestos may also be used in place of platinized silica gel. 

Phosphorus pentachloride, 99 Phosphotungstic acid, 132 ether complex, 133 Platinized asbestos, 160 Platinized silica gel, use in preparation of hydrogen bromide, 162... 

Platinic compounds [see specific compounds under Platinum (IV)] Platinized asbestos, 1 160 3 129 Platinized silica gel, use of, in preparation of hydrogen bromide, 1 152... 

Hydrogen Bromide. /Inhydrous hydrobromic acid. BrH mol wt 80,92, H 125%, Br 98.75%. HBr- Prepd commercially by direct combination of the elements at 375 preferably over a catalyst such as platinized silica gel or pla -t ini zed asbestos Richards, I lomgschmid, J. Am. Chem. Soc. 32, 1581 (1910) Smyth, HUchcock, ibid. 55, 1830 (1933) Schneider, Johnson, Inorg. Syn. 1, 152 (1939). Lab procedure from tetra hydro naphthalene and bromine Mil Her, Monatsh. 49, 29 (1928) Duncan, Inorg. Syn. 1, 151 (1939) Schmeisser in Handbook of Preparative Inorganic Chemistry... 

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