EFFECT OF TEMPLATE CONSTRAINTS ON ADSORPTION PROPERTIES OF SYNTHETIC CARBONS PREPARED WITHIN THE GALLERY OF LAYERED DOUBLE HYDROXIDES

Mg-Al layered double hydroxides have been synthesized and 1,5-naphthal ene disulfonate dianions have been intercalated; the organic molecules were carbonized within the layered framework. For comparison, a refer ence carbon was prepared from the sodium salt of the 1,5-naphthalene d isulfonic acid precursor using conventional carbonization under the sa me thermal and post-treatment conditions. The surface properties of th e carbonized product extracted from the carbon-mixed oxide nanocomposi te have been studied by adsorption techniques and the results compared to the adsorption characteristics of the reference carbon. The sorpti on of nitrogen at 77 K and carbon dioxide at 298 K demonstrate that, a lthough the two carbons have almost the same specific surface area and total pore volumes, there is a significant difference in their microp ore structure. Micropore size distributions calculated from adsorption isotherms of methane and sulfur hexafluoride at near ambient temperat ures reveal a more heterogeneous micropore structure for the template derived carbon compared to the reference. The factors controlling micr opore structure development during two-dimensional carbonization are d iscussed based on DTA, results of sorption of carbon dioxide and FTIR spectroscopic measurements. Copyright (C) 1996 Elsevier Science Ltd