Direct Amination of Benzene with NH3 and H2O2 Over Hierarchical Fe,Cu/ZSM-5 Prepared by Post-synthesis Treatment of Nanocrystallite B–ZSM-5

Wang, Honglin; Ma, Zhen; Yang, Jianguo

doi:10.1007/s10562-019-03026-9

Cited by 9 publications

(2 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 792 cm –1 band was attributed to the symmetric tensile deformation of the Si–O–Si frame; the 1090 cm –1 band was attributed to the asymmetric stretching of Si–O–Si; and the strong band at 1224 cm –1 was related to the asymmetric internal tetrahedral vibration of SiO 4 . , The 450 cm –1 , 546, 792, and 1224 cm –1 bands of Cu–ZSM-5 coincided with the corresponding bands of Na–ZSM-5. However, the 1090 cm –1 band of Cu–ZSM-5 decreased in size compared to that for Na–ZSM-5, which was attributed to the fracture of the asymmetric stretching of Si–O–Si by the ion-exchange stirring process . In comparison to those of the fresh sample, the four- and five-membered ring bands of the sample treated with water vapor were greatly reduced.…”

Section: Resultsmentioning

confidence: 83%

“…However, the 1090 cm −1 band of Cu−ZSM-5 decreased in size compared to that for Na−ZSM-5, which was attributed to the fracture of the asymmetric stretching of Si−O−Si by the ion-exchange stirring process. 33 In comparison to those of the fresh sample, the fourand five-membered ring bands of the sample treated with water vapor were greatly reduced. With the increase in the water vapor content, each band decreased greatly, which proved that the degree of destruction of the catalyst skeleton structure was closely related to the water vapor content.…”

Section: Uv−vis Resultsmentioning

confidence: 93%

See 1 more Smart Citation

Effect of Water Vapor on Catalytic Decomposition of NO over Cu–ZSM-5: A Mechanism and Kinetic Study

et al. 2020

View full text Add to dashboard Cite

Cu–ZSM-5 has great potential for the direct catalytic decomposition of NO in flue gas. However, NO conversion is significantly inhibited in the presence of water vapor, and the mechanism for this inhibition process has not been identified. In this study, a series of experiments are carried out to simulate the flue gas in coal-fired power plants. The reaction mechanism for NO decomposition and the corresponding kinetics are determined. The experimental results show that NO conversion clearly decreases as the water vapor content increases. A variety of characterization methods were applied to the samples treated with water vapor. Brunauer–Emmett–Teller shows the change from micro- to mesopores under the action of water vapor, while X-ray diffraction shows grain growth, fragmentation, and agglomeration under the action of water vapor. Scanning electron microscopy shows that the surface of the grains is corroded by water vapor, while ultraviolet–visible spectroscopy shows the presence of Al3+ in the condensate. Finally, Raman and Fourier transform infrared spectroscopy show that the skeleton structure of the catalyst is destroyed by water vapor. CuO is detected as a result of changes in the copper species, which is caused by the destruction of the skeleton structure. Furthermore, there is competition between NO and H2O in the adsorbing process. The steady-state kinetics of Cu–ZSM-5 show that the decomposition rate of NO increases with the increase in the NO concentration, [Cu–O–Cu]2+ dimer number, and chemical kinetic parameters. The reaction rate constant k 1 is positively correlated with the temperature. Additionally, there is a side reaction between the dimer and H2O, which can reduce the amount of dimer and the impact factor b. Finally, the reaction rate constant k 1 and the impact factor b increase with an appropriately increasing temperature.

show abstract

Section: Resultsmentioning

confidence: 83%

Section: Uv−vis Resultsmentioning

confidence: 93%