Comparative NO2 adsorption was studied over microcrystalline zeolite Y and two chromium-exchanged samples, at between 251 and 403K. Maximum adsorptive capacities, and heats of adsorption, were found very similar for the three zeolites. An analysis of the adsorption kinetics established the diffusion coefficient to be 1.1 x 10−16m2/s, whatever the chromium content in the zeolite.

Adsorption of NO2 on Modified Y Zeolites. J.M.Goupil, J.F.Hemidy, D.Cornet: Zeolites, 1982, 2[1], 47–50