42.     ANDERSON, R. B., AND EMMETT, P. H.  Surface Complexes on Charcoal.  Gas Evolution as a Function of Vapor Adsorption and of High-Temperature Evacuation.  Jour. Phys. and Colloid Chem., vol. 51, 1947, pp. 1308-1329; Chem. Abs., vol. 42, 1948, p. 1410.

                Gases evolved, on evacuating charcoals for gas masks, to 1,200° were collected at 300° intervals and analyzed for CO, CO₂ H₂, H₂O, and CH₄.  The O₂-containing gases were formed by decomposition of surface complexes and by reduction of the inorganic oxides present as ash.  CO and CO₂ evolution reached a maximum at about 600° for charcoals prepared by the ZnCl₂ process and at 900°-1,200° for those prepared from coal.  The total O₂-containing gases evolved were always equivalent to less than 50% of the charcoal surface.  Extracting charcoals with HF and reexposing them to air resulted in about a 20-fold increase in the amount of CO evolved on heating the samples to 600°.  H₂ evolution in the temperature range 600°-1,200° amounted to 25-147 cc. for the various charcoals.  Activation of the charcoals by steam was shown to form very little O complex.  The amount of CO and CO₂ displaced from the surface complex by the adsorption of CCI₄, H₂O, or chlorobenzene was found to be equivalent to less than 0.01 cc. per gm.  NH₃ at 750°-900° formed a N complex on the charcoals that was more stable than the O complexes.

                ANDERSON, R. B., AND HALL, W. K.  Modifications of the Brunauer, Emmett and Teller Equation, II.  See abs. 41.