One-step oxidation of benzene to phenol with nitrous oxide over Fe/MFI catalysts

Catalytic effect of transition metals on microwave-induced degradation of atrazine in mineral micropores

“…The selective formation of hydroxylated degradation product is consistent with the oxygen-insertion reaction pathway (Fig. 5c) catalyzed by iron-exchanged zeolites (Jia et al, 2004;Wood et al, 2004). The formation of the deethylated products was more significant than the deisopropylated products on Fe/CBV-720, probably because of weaker coordination of the isopropyl nitrogen to iron compared to copper.…”

“…Transition metals were exchanged onto the dealuminated Y zeolites by equilibrating them with solutions of the respective metal cations at room temperature followed by thermal treatment to stabilize the cationic metallic species, which is a common way of preparing metal-exchanged zeolites (e.g., Groothaert et al, 2005;Jia et al, 2004;Larsen et al, 1994;Li et al, 2008;Yahiro and Iwamoto, 2001). Specifically, copper-exchanged zeolites were prepared by equilibrating 5 g of dry zeolites with 100 mL of CuCl 2 solution for 48 h under constant stirring, followed by filtration to remove the solution.…”

“…It should be noted that the reactivity of oxygen coordinated to the FeO þ centers was so high that it could insert into the non-activated CeH bonds of hydrocarbons under ambient conditions, leading to selective formation of the hydroxylated products (Panov et al, 1998). Therefore, an additional reaction pathway of oxygen-insertion could exist on the iron-exchanged zeolites compared to the copperexchanged ones (Jia et al, 2004;Wood et al, 2004): 3.5.…”

Stable Fe/ZSM-5 Nanosheet Zeolite Catalysts for the Oxidation of Benzene to Phenol

“…9,12−17 It has been found that only a fraction of these “α-oxygen” are able to oxidize benzene to phenol. 5,15 Steaming of isomorphously substituted Fe/ZSM-5 zeolite is crucial to enhance the number of extraframework Fe ions. 9,18 During steaming, Fe–O–Si bonds in Fe/ZSM-5 crystals are broken, resulting in the migration of Fe from the zeolite framework to extraframework locations.…”

Transition metal substituted polyoxometalates and their application in the direct hydroxylation of benzene to phenol with hydrogen peroxide

“…Benzene hydroxylation is done through three main pathways. The first route involves passing gas over zeolite catalysts, such as Fe-ZSM-5, Fe-TS-1, and Fe/MFI, with N 2 O as an oxidant at temperatures of over 600 K. In this method, the selectivity is 90%, and the benzene conversion is 20% [4][5][6][7][8]. However, the availability of N 2 O as an oxidant is limited because of the high temperature in the reaction process and the deactivation of the catalysts by heavy coke formation.…”