In situ preparation of mesoporous Fe/TiO2 catalyst using Pluronic F127-assisted sol-gel process for mid-temperature NH3 selective catalytic reduction

Ultralow-Temperature NOx Reduction over SmMn2O5 Mullite Catalysts Via Modulating the Superficial Dual-Functional Active Sites

“…57,58 When NO + O 2 is introduced, the weakly adsorbed NH 3 species vanish, meanwhile NO − species (1180 cm −1 ), bidentate nitrates (1564 cm −1 ), and NO 2 (1614 cm −1 ) appear. 28,59,60 Different from the SM-E catalyst, NO − species over the S-M catalyst are oxidized to more stable bridged nitrates. These results indicate that SM- E can adsorb and activate more NH x species, and the more generated active nitrites and NO 2 species are in favor of the reaction after introducing NO x .…”

Study on the catalytic activity and hydrothermal stability of one-pot synthesized Fe-based FER zeolites for NH3-SCR

“…8, the TPR peaks of the fresh and aged zeolites are observable at around 310 °C, 370 °C, 405–430 °C, 480 °C, 530 °C and 620 °C. According to the literature, 5,35,36,47 the reduction signals at around 310 °C (peak A) and 370 °C (peak B) can be ascribed to the reduction of isolated Fe 3+ to Fe 2+ at different ion-exchange sites of zeolites, while those at around 405–430 °C (peak C) are attributed to the reduction of oligo-nuclear Fe x O y clusters such as dimeric Fe 3+ species. In addition, the reduction signals in the >480 °C range originate from the reduction of iron oxide species with different particle sizes, as the reduction temperature of iron oxide clusters increases with their particle size according to Brandenberger et al 48 Combined with the XRD and UV-vis results, the reduction peaks at around 480 °C (peak D) and 530 °C (peak E) can be attributed to the highly aggregated Fe x O y species, while the broad reduction peak at around 620 °C of the IM-Fe/SSZ-20-A zeolite can be ascribed to the reduction of large Fe 2 O 3 nanoparticles.…”

“…6, overlapped UV bands centred at about 216, 265, 350, 430, 520 and 660 nm can be observed in the UV-vis spectra of the zeolites. According to numerous literature reports, 1,30–40 the UV bands at 216 and 265 nm can be attributed to isolated Fe 3+ ions in tetrahedral and higher coordination of zeolites, respectively; the UV band at around 350 nm is assigned to the presence of oligo-nuclear Fe x O y clusters such as ferric ion dimers and trimers, oligomers, etc. , while the UV bands at >400 nm originate from larger iron oxides such as Fe 2 O 3 nanoparticles.…”

“…In addition, the reduction signals in the >480 °C range originate from the reduction of iron oxide species with different particle sizes, as the reduction temperature of iron oxide clusters increases with their particle size according to Brandenberger et al 48 Combined with the XRD and UV-vis results, the reduction peaks at around 480 °C (peak D) and 530 °C (peak E) can be attributed to the highly aggregated Fe x O y species, while the broad reduction peak at around 620 °C of the IM-Fe/SSZ-20-A zeolite can be ascribed to the reduction of large Fe 2 O 3 nanoparticles. 35–37 The deconvoluted H 2 -TPR profiles and the corresponding quantitative results are shown in Table 3 and Fig. S4 and S5 †.…”

Peptide-Decorated Ultrasmall Superparamagnetic Nanoparticles as Active Targeting MRI Contrast Agents for Ovarian Tumors

“…Triblock copolymer Pluronic F127 (F127) is often applied as a template for its amphiphilic molecule of polyoxyethylene–polyoxypropylene–polyoxyethylene (PEO-PPO-PEO). F127 can spontaneously form well-dispersed micelles with the inner side composed of hydrophobic PPO and a few PEO and the outer shell composed of hydrophilic PEO in water. − Therefore, F127 micelles can provide a local hydrophobic environment for the crystallization of iron oxide in aqueous solution, and some of the iron oxide crystals can grow in F127 micelles and be regulated by the micelle confinement effect (abbreviated as USPIOs@F127). However, the steric hindrance effect of F127 micelles is still not strong enough and USPIOs@F127 were easily aggregated together.…”