Distribution of Al and adsorption of NH₃ and pyridine in ZSM-12: a computational study.

Feng, Gang; Lian, Ying-Ying; Yang, Deqin; Liu, Jianwen; Kong, Dejin

The distribution of Al and the adsorption of NH3 and pyridine in both Na-form and H-form ZSM-12 were investigated using dispersion-corrected density functional theory. It was found that the energy differences for Al atoms in the different T sites of ZSM-12 (both H form and Na form) were less than 0.3 eV, which indicates that the Al atoms could distribute in all kinds of T sites in ZSM-12. In addition, the small energy difference indicates that both H and Na atoms could stay in either the small cage or the main channel of ZSM-12. The adsorption of NH3 and pyridine on NaZSM-12 is weak, while the adsorption of NH3 and pyridine on HZSM-12 is strong, as they could form NH4 and NC5H6 species in the presence of protons. Both NH3 and pyridine could adsorb on the Lewis Al3 sites in HZSM-12, while the adsorption of NH3 and pyridine on the Lewis acid sites are less stable than on the Brønsted acid sites of ZSM-12.

PYRIDINE; ADSORPTION (Chemistry); DENSITY functional theory; BRONSTED acids; LEWIS acids; LEWIS acidity

Canadian Journal of Chemistry, 2013, Vol 91, Issue 10, p925

0008-4042

Academic Journal

10.1139/cjc-2013-0135