“…But we did not observe the increase in the band intensity of silanol groups after the deboronation, unlike the case for beta zeolite that shows more silanol groups after the deboronation [19]. The intensity of the broad band at 3700-3400 cm −1 is decreased with the increased pretreatment temperatures due to the dehydroxylation of the silanol groups [18], and some defects could be produced after the deboronation and the subsequent calcination.…”
Section: Deboronationcontrasting
confidence: 77%
“…For deboronated samples, the 3740 cm −1 band remains unchanged, but the broad band at 3700-3400 cm −1 shifts to lower frequencies. This is because those silanol groups are derived after the boron atoms were removed, and the silanol groups may be interacted with each other via the hydrogen bonding [18]. But we did not observe the increase in the band intensity of silanol groups after the deboronation, unlike the case for beta zeolite that shows more silanol groups after the deboronation [19].…”
“…But we did not observe the increase in the band intensity of silanol groups after the deboronation, unlike the case for beta zeolite that shows more silanol groups after the deboronation [19]. The intensity of the broad band at 3700-3400 cm −1 is decreased with the increased pretreatment temperatures due to the dehydroxylation of the silanol groups [18], and some defects could be produced after the deboronation and the subsequent calcination.…”
Section: Deboronationcontrasting
confidence: 77%
“…For deboronated samples, the 3740 cm −1 band remains unchanged, but the broad band at 3700-3400 cm −1 shifts to lower frequencies. This is because those silanol groups are derived after the boron atoms were removed, and the silanol groups may be interacted with each other via the hydrogen bonding [18]. But we did not observe the increase in the band intensity of silanol groups after the deboronation, unlike the case for beta zeolite that shows more silanol groups after the deboronation [19].…”
“…The high Pt dispersion on H-USY(420) might be caused by mesopores with ca. 2 nm diameter formed by the deep dealumination of USY 20) . The influence of water vapor was then studied because the flue gas from incinerators always contains a large fraction of water vapor.…”
Section: Combustion Of Dibenzofuran (Dbf)mentioning
The catalytic combustion of dibenzofuran and chlorobenzene, model compounds for dioxin, was investigated on Pt supported zeolite catalysts. Among transition metals, such as Pd, Au, Ni, etc., Pt supported on H-USY zeolite was the most active and stable for the combustion of dibenzofuran into CO2 and water at 573 K. The reduction treatment on Pt/H-USY before the reaction gave high activity compared with the oxidation treatment. The con version of dibenzofuran was governed by the dispersion of Pt particles irrespective of the acidity and porosity of support materials including zeolites, mesoporous silica and silica gel. The combustion of chlorobenzene on Pt/ zeolite proceeded at much higher temperature than that of benzene. The conversion of chlorobenzene was accel erated by the presence of water vapor in the reactant and the acid sites on zeolite. The activity of Pt/H-ZSM-5 for the combustion of polychlorodibenzofuran, one of dioxin, was discussed from the combustion results of dibenzofuran, chlorobenzene and benzene.
“…Lattice termination silanol groups are mainly located on the external surface Hydroxyl nests can be produced in the process of steaming (heating to high temperatures in the presence of water vapor), as described by the equation shown in Figure 1.3 [18,19]. The removal of framework aluminum also occurs during steaming, forming non-framework aluminum species such as Al(OH) 3 .…”
Section: Spectroscopymentioning
confidence: 99%
“…In addition, gasphase absorptions have been subtracted from each of the FT-IR spectra. 3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,21,23,25,27,30 min, respectively. The blank grid is used as a reference.…”
Synthetic zeolites are used widely throughout the petroleum refining and chemical process industries as selective adsorbents, catalysts and ion exchangers. The research described in this thesis focuses on the characterization and environmental applications of faujasite zeolites, including nanocrystalline Y zeolites that have particle sizes less than 100 nm.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.