Mechanistic Study on Adsorption and Oxidation of NO over Activated Carbon

Themechanism of NO adsorption and oxidation over activated carbon at lowtemperature has been studied by NO adsorption and oxidation, NO2adsorption and Fourier transform infrared spectroscopy. The results show thatwhen oxygen is present, activated carbon catalyses NO oxidation into NO2and a stable NO conversion rate is achieved. NO is adsorbed in the form of (NO)2due to the confinement effects of the activated carbon micropore. (NO)2is oxidized into NO2 by oxygen. The disproportionation of NO2gives NO and NO3, that causes the peak of the maximum NOconcentration. When the active sites are saturated by NO3, NO2adsorption and disproportionation gradually diminish, that results in NO2breakthrough and increases the concentration of NO2 to thestationary one. At the same time, the concentration of NO gradually decreasesto the stationary one after the maximum.

Description of an Active Carbon Micropore Size Distribution Based on the Horvath—Kawazoe Equation Adapted to Benzene Adsorption Isotherms

The Horvath–Kawazoe equation has been used for the determination of the pore size distribution (PSD) of four fractions of active carbon separated by elutriation on the basis of their different degrees of activation. A comparison of the pore size distribution functions for argon and benzene as adsorbates has been undertaken. For both adsorbates, correction factors including the adsorption in mesopores have been evaluated. The influence of these corrections on the PSD functions has been discussed. Quantitative evaluations of the PSD functions for these two different adsorbates and a comparison with the results of small-angle X-ray scattering measurements leads to the conclusion that it is possible to use the benzene isotherm as well as those of other adsorbates.