Inorganic oxide-modified carbon molecular sieve

In this paper we briefly review the important aspects of carbon molecular sieve materials with special emphasis on their use in catalysis, and our most recent results with composite structures that we have termed inorganic oxide-modified carbon molecular sieves (IOM-CMS). The literature on carbon molecular sieves, particularly patents, is large and growing, with European and Japanese researchers dominating in recent years. 

In some instances the method for carbon determination has to be modified, e.g., the determination of trace amounts of what is referred to as dissolved organic carbon in water after inorganic carbon has been removed. This type of carbon determination involves wet oxidation activated by silver ions in a solution of potassium persulphate in sulphuric acid. The oxidation of organic compounds gives carbon dioxide, which is adsorbed by molecular sieves. The molecular sieves are then heated in a flow of helium to desorb the carbon dioxide, the amount of which is measured by a TCD. The lowest concentration of organic carbon that can be measured in water is 0.2—2ppm [55]. The application of chromatographic elemental analysis to the determination of the total carbon content in water has been described [56]. 

A recent development was to prepare carbon based molecular sieves which are funcionalized with inorganic oxides and supported metals. The main objective is to combine the molecular sieving properties of the carbon with surface chemical and physical properties of the inorganic oxides in one composite structure. Sharma and Seshan [9] reported copper modified CMS for the selective removal of oxygen at temperatures below 200 C. At higher temperatures, oxygen can be reversible adsorbed only if present in trace amounts. 

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