The preparation and properties of some activated carbons modified by treatment with phosgene or chlorine

✍ Scribed by C. Richard Hall; Richard J. Holmes

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 368 KB
• Volume: 30
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(92)90077-a

✦ Synopsis

Treatment of coal or coconut shell activated carbons with either phosgenc or chlorine at 180°C followed by washing with methanol or water results in chlorinated carbons with very similar pore structures to their precursors. Water adsorption experiments show that the modified materials arc relatively hydrophobic, presumably as a result of replacement of oxygen-containing surface groups by chlorine. Adsorption of the model hydrophobic vapour chloropicrin from humid air is usually better for the modified carbons which, unlike the controls. do not appear to bc subject to degradation in performance on ageing in a humid atmosphere.

The stability of the modified carbons is probably a consequence of the chlorination of those sites on the control carbons that are prone to ready oxidation or hydroxylation.