Mechanism of catalytic decomposition of NO by Cu-ZSM-5
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Graphical Abstract
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Abstract
Catalytic decomposition of NO by Cu-ZSM-5 has potential application. In order to reveal the catalytic decomposition mechanism of NO over Cu-ZSM-5, the adsorption of NO over short-range Cu+ pairs in Cu-ZSM-5 was simulated based on density functional theory. The reaction pathways of NO decomposition assisted by the by-products N2O and NO2 were also proposed. The results showed that the double nuclear copper-oxygen species was an important active centre. During the reaction, the highest activation energy (171.39 kJ/mol) was required for the decomposition of the by-product NO2 on the binuclear copper-oxygen species. While that for the decomposition of N2O was 86.92 kJ/mol, suggesting that the decomposition of NO2 was more difficult. The desorption energy of N2 and O2 were 28.43 and 100.78 kJ/mol, respectively. The rate determining step was O2 desorption. NO acted both as a reactant and a key reductant for the redox cycle of the active centre of Cu-ZSM-5 during the process.
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