Capturing nitrosamines by zeolite A: Molecular recognition in subnanometer space

The adsorption and catalytic degradation of nitrosamines by zeolite A with cesium, potassium, sodium, or calcium cation was systemically studied in the research reported in this article. The results of instantaneous adsorption, temperature-programmed surface reaction, and in situ Fourier transform infrared spectroscopy measurements proved the adsorption of the bulky nitrosamines, N′-nitrosonornicotine (NNN) and N-nitrosopyrrolidine, on the zeolite A with a pore diameter of only 0.2-0.5 nm. Moreover, thermogravimetric-mass spectrometry analysis revealed the different adsorption and degradation manners of NNN on various samples of zeolite A, which will be discussed in terms of electrostatic attraction and geometric confinement provided by the zeolite.