STUDIES ON SOLID CATALYSTS WITH A BASIC CHARACTER .2. NATURE OF ACIDIC AND BASIC CENTERS ON SURFACE OF SODIUM-SILICA CATALYSTS

The surface properties of silica impregnated with varying sodium amounts have been investigated. Specific surface, pore volume, and mean pore radius were determined. Water content in, and infrared spectra of the water molecules bonded to the catalysts were studied. Adsorption was investigated of γ-picoline, pyridine, ammonia on the surfaces of the catalysts. Consistency of the observed ammonia adsorption with Langmuir's and Temkin's adsorption isotherms was examined. Adsorption rate of ammonia and its agreement with the Elovich kinetic equation was studied. The heat of adsorption and the maximum number of ammonia adsorption centers were calculated. The quantities determined were investigated as functions of the amount of milligram-ions of Na+ per square meter of catalyst surface area, experimental temperature, and catalyst degassing temperature. As the sodium content in the silica surface was increased, adsorption of the pyridine bases, ammonia, and carbon dioxide rose. © 1969.