High-temperature treatment effect of microporous carbon on ordered structure of confined SO2

The X-ray diffraction (XRD) of SO2 molecules adsorbed in micropores of acti vated carbon fiber (ACF) was measured at 303 K. Effect of pore width and hi gh-temperature treatment (HTT) of ACF on the XRD of SO2 in micropores were examined. The HTT gave rise to a more dipole-oriented structure of SO2 mole cules in micropores of 1.1 nm width, whereas the opposite effect was observ ed in micropores of 0.7 nm. The intensified image potential of an SO2 molec ule for the heat-treated graphitic pore wall should stabilize the dipole-or iented structure in the case of 1.1 nm micropores, while the heat-treatment provides defective structures in the narrow micropore system. The presence of O-2 stabilized the dipole-oriented structure of SO2 molecules in the mi cropore. (C) 2000 Elsevier Science B.V.