Density Functional Theory Calculation on the Dissociation Mechanism of Nitric Oxide Catalyzed by Cu4Cluster in ZSM-5 (Cu4-ZSM-5) and Bimetal Cu3Fe in ZSM-5 (Cu3Fe-ZSM-5)

Abstract Zeolite‐based catalysts have been investigated as a well‐known catalyst in a selectively catalytic reduction (SCR), in the conversion of NO to N 2 molecule. Here we have performed periodic DFT calculations to simulate pure metal, Cu 4 , and bimetal Cu 3 Fe clusters, on the ZSM‐5 by introducing a single Al atom in the unit cell of ZSM‐5 (Si/Al ratio=95). The calculated results show that the most stable structures of both Cu 4 and Cu 3 Fe clusters in ZSM‐5 are both T d configuration. In addition, the NO bond length would be elongated from 1.15 Å to 1.25∼1.30 Å in the adsorption of NO on metal‐cluster stabilized zeolites (both Cu 4 ‐ZSM‐5 and Cu 3 Fe‐ZSM‐5), being longer than the counterparts on single‐metal anchored zeolites. Furthermore, the calculated NO bond cleavage barrier on Cu 3 Fe‐ZSM‐5 was lower than its counterparts on Cu 4 ‐ZSM‐5. To understand the electronic properties, we performed the calculation of Bader charge analysis and local densities of states, and the result was explicable.