Adsorption and room temperature degradation of N-nitrosodiphenylamine on zeolites

Abstract

N-Nitrosodiphenylamine (NDPA) is selected as a model compound to reveal the specific adsorption and catalytic function of zeolites in the removal of carcinogenic nitrosamines from the environment. The bulky NDPA molecule is indeed adsorbed in the zeolite KA having a small aperture, by insertion of the –N–NO group into the channel and involving a specific interaction between the nitrosamine and the zeolite. Degradation of NDPA at room temperature on zeolite is reported for the first time, revealing the potential applicability of zeolites to eliminate nitrosamines under mild conditions. The acidity of zeolite is the key factor determining its ability to degrade NDPA and, among the zeolites evaluated, Hβ is the most effective catalyst with an activity much higher than that of other zeolites at ambient temperature.