Adsorption of carbon dioxide by magnesia studied by use of infrared and isotherm measurements

Abstract

The adsorption of carbon dioxide on magnesia (prepared by hydrolysis of magnesium methoxide) has been studied by measurements of the i.r. spectra of carbon dioxide which had been adsorbed at various temperatures, supplemented by gravimetric measurements of adsorption isotherms at temperatures ranging from –97·9 to 500 °C. Three types of adsorption were encountered: (I) a rapid physical adsorption; (II) a slow chemisorption involving the formation of a bidentate carbonate ion; and (III) a still slower chemisorption which resulted in the formation of a carbonate ion similar to that present in bulk magnesium carbonate. (I) and (II) occur at temperatures up to and including room temperature; and (II) and (III) at temperatures from that of the room upwards.