Carbon nanotubes were prepared and investigated as sorbents for NO, SO2, an
d CO2 in the presence of O-2. The preliminary results indicate that they ar
e a good and reversible sorbent for NO removal at room temperature. An upta
ke amount of 78 mg/g of NOx was obtained by TGA when the carbon nanotubes w
ere exposed to 1000 ppm NO + 5% O-2/He for 120 min. The equilibrium amount
was near 90 mg/g after 12 h. TPD profiles show that NO2 and NO desorb from
the NOx-saturated carbon nanotubes at well below 300 degreesC. FTIR spectra
indicate that the adsorbed species are nitrates and trace amounts of NO2 a
nd (NO)(2) dimers. By comparison, only 29 mg/g of SO2 (at 500 ppm) and 2 mg
/g of CO2 (at 10%) are adsorbed onto the carbon nanotubes in 120 min.