Carbon molecular sieves with stable hydrophobic surfaces

The effect of interactions of O2 and H2O with CMS surfaces on their performance was studied under ambient conditions by using O2 and Ar as molecular probes. Such interactions deteriorate the adsorption-desorption behavior of CMS and exhibit an adverse impact on their performance. Treatments of CMS with Cl2 and H2 were investigated for stabilizing their surfaces. Treatment with H2 at 5.5 MPa and 150°C was found to eliminate strong interactions with O2 and H2O by passivating the active sites, thus resulting in a stable CMS surface.