Adsorption of parent nitrosamine on the nanocrystaline M-ZSM-5 zeolite: A density functional study

作者：Roohi Hossein^*; Jahantab Mahjoubeh

来源：Journal of Chemical Sciences, 2013, 125(6): 1607-1618.

• Adsorption
• 10T cluster model
• nitrosamine-M-zeolite complexes
• NBO
• AIM

The adsorption of parent nitrosamine (NA) on the Bronsted acid sites of M-ZSM-5 (M = H, Li and Na) zeolites have been investigated via the utilization of 10T cluster model by density functional calculations, at the B3LYP/6-311++G(d,p) level. Two A and B complexes with two types O(N) center dot center dot center dot M and NH center dot center dot center dot O-z interactions were predicted from adsorption of nitrosamine on the M-zeolite clusters. The comparison of interaction energies shows that the order of energies for adsorption of NA on the Bronsted acid site of M-ZSM-5 is Na < Li < H for the A complexes and Li < H for the B complexes. The calculated adsorption enthalpy of NA on the Bronsted acid site of 10T cluster of M-ZSM-5 catalyst ranges from -14.41 to -52.95 kJ/mol. The acid strength of H-ZSM-5 was found to exceed those of the corresponding to the alkali metal ion-exchanged zeolites. The results reveal that the interaction between hydrogen of NA and O-z of framework is weaker than O(N) center dot center dot center dot M one. The NH center dot center dot center dot O-z and O(N) center dot center dot center dot H-z hydrogen bonds in these complexes are electrostatic and partially covalent in nature, respectively. The results of natural bond orbital (NBO) analysis showed that charge transfer occurs from NA to M-zeolite cluster.

• 出版日期2013-11