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 a t various temperatures, supplemented by gravimetric measurements of adsorption isotherms a t temperatures ranging from -97.9 to 500 " C . Three types of adsorption were encountered : (I) a rapid physical adsorption ; (11) a slow chemisorption involving the formation of a bidentate carbonate ion; and (111) a still slower chemisorption which resulted in the formation of a carbonate ion similar to that present in bulk magnesium carbonate. (I) and (11) occur a t temperatures up to and including room temperature ; and (11) and (111) a t temperatures from that of the room upwards.

Presence and detection of carbonates on the Martian surface

“…Maxwell distribution at T = 273 K and p = 20 mbar [Gregg and Ramsay, 1970] leads to the rate 4.84 x l02• cm -2 s-• collisions of CO2 molecules with the surface. The resulting rate of surface coverage is 9.44 x 10 6 s -•.…”

“…Finally, some conclusions are drawn in section 5. Unfortunately, no direct data pertaining to the sticking probability of CO2 on the CaCO3 surface exist, and we have to rely on experimental information regarding adsorption of CO2 on BeO and MgO [Stuart and Whateley, 1965;Gregg and Ramsay, 1970]. It is helpful to note in this connection that the adsorbate interacts mainly with basic sites of the adsorbant, and as it has been pointed out by , the basicity of alkaline earth metal oxides goes in the order BeO < MgO < CaO.…”

Pioneers of Adsorption Science 2. Sidney John Gregg

“…Gregg and Langford 1969;Gregg and Ramsay 1970) and to extend particular areas of research (Gregg and Sing 1976). One such area was the characterization of microporous materials.…”

Graphene-manganese oxide hybrid porous material and its application in carbon dioxide adsorption

“…Many kinds of metal oxides display well in the performance of carbon dioxide adsorption, such as calcium oxide [9] and magnesium oxide [10]. Besides the basic sites contained in the solid adsorbent, the surface area is also an important factor.…”

“…For the latter one, there are four main approaches: cryogenic distillation, membrane purification, absorption with liquids [2], and adsorption using solids [3,4]. Using solid adsorbent is widely considered, such as zeolites [5,6], activated carbons [7,8], metal oxides [9,10], and supported amines [11].…”