The behavior of iodine in graphite

✍ Scribed by F.J. Salzano

• Publisher: Elsevier Science
• Year: 1964
• Tongue: English
• Weight: 721 KB
• Volume: 2
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(64)90030-2

✦ Synopsis

The adsorption of iodine on NatIonal Carbon type TSX graphite was studied nt 100, 200, 500 and SOO"C, over the pressure range 0.01-15 mm Hg, using a tracer technique. Abow 200 C iodine was chemisorbed on a small fraction of the graphite surface. At 100°C the iodine xvas held on the graphite by both chemisorption and physical adsorption. The surface area of the graphite. determined from the 100°C iodine adsorption isotherm using the B.E.T. theory, was found to hc in vod agreement with surface area values obtained from nitrogen isotherms at -195°C. No relation \a: found between the amounts of iodine adsorbed on various samples and their surface area, at conccntrations below one monolayer. The adsorption of iodine was enhanced by high tcmpcratun~ outgassing (2OOO'C) and contact with water vapor at 900°C. A small fraction of the iodinr adsr,rbed at 25 and 100°C could not be removed from the graphite by heating in 'uacuo at 950 C. The amount of iodine irreversibly adsorbed at 25"C, in saturated iodine vapor, was approximately proportional to the reversible iodine adsorption at higher temperatures.