Micropore filling by supercritical NO on external surface-modified microporous carbons

Abstract

External surfaces of microporous activated carbon fibres (ACFs) have been selectively modified with magnetites through molecular adsorption and successive decomposition of an organic iron compound (iron acetylacetonate : FeAA) with molecules too large to enter the micropores. The decompositon of FeAA adsorbed on ACF at 623 K for 3 h in the presence if water vapour gave the external surface modified ACF with magnetites. The external surface modified ACF was characterized by nitrogen adsorption, X-ray diffraction and magnetic measurements; those suggested that the fine magnetites produced from FeAA are not in the micropores, but on the external surface. The micropore filling ability of the external surface modified ACF for supercritical nitrogen monoxide (NO) was examined; a marked enhancement in the micropore filling of NO in the lower-pressure region by the magnetite modification was observed.