The Effect of Different Active Sites on the Catalytic Activity of Fe-ZSM-5 Zeolite for N2O Direct Decomposition

Abstract

Fe-modified ZSM-5 zeolites (Si/Al = 25) were prepared by adopting the liquid ion-exchange method with nitrate and oxalate of iron as Fe precursors and their catalytic performance was studied in the N 2 O decomposition reaction. The results of FT-IR and H 2 -TPR investigations indicated that (i) part of the iron ions could replace Brön-sted acid protons at the straight channel wall (a sites), intersection of straight and sinusoidal channels (b sites), and sinusoidal channel wall (c sites) within the ZSM-5 zeolite; and (ii) different Fe precursors gave rise to various distributions of a, b, and c sites. We observed that the Fe-ZSM-5 catalyst prepared with iron oxalate as Fe precursor outperformed the ones prepared with iron nitrate as Fe precursor in the direct decomposition of N 2 O. Furthermore, the catalytic activity of iron ions located at the a sites was higher than those of iron ions located at the b and c sites.

Catalytic oxidation of trichloroethylene over Fe-ZSM-5: Influence of the preparation method on the iron species and the catalytic behavior

“…The acidity of the catalysts prepared by IMP and SSIE decreased around 20%. This is because the Fe can get exchanged at ␣, ␤ or ␥ position in the zeolite, which in turn affects differently to the total acidity [17].…”

One-pot synthesis of iron doped mesoporous silica catalyst for propane ammoxidation

“…Iron doped microporous material Fe-MFI and the [Fe]-MFI represent well known and abundantly studied catalytic materials for a variety of industrial reactions, among them for example the selective oxidation of benzene to phenol, [1][2][3] the reduction of NO x and N 2 O with ammonia or hydrocarbons [4][5][6][7][8][9] and also the direct decomposition of N 2 O. 10,11 Although this material reaches very interesting results in the above mentioned reactions, it also suffers from drawbacks connected to the diffusion limitations (due to its microporositypore size is 0.51 × 0.56 nm). In order to overcome these problems several approaches have been proposed and studied.…”