Low-Temperature Catalytic Ozonation of Multitype VOCs over Zeolite-Supported Catalysts

Abstract

Volatile organic compounds (VOCs) are an important source of air pollution, harmful to human health and the environment, and important precursors of secondary organic aerosols, O3 and photochemical smog. This study focused on the low-temperature catalytic oxidation and degradation of benzene, dichloroethane, methanethiol, methanol and methylamine by ozone. Benzene was used as a model compound, and a molecular sieve was selected as a catalyst carrier to prepare a series of supported active metal catalysts by impregnation. The effects of ozone on the catalytic oxidation of VOCs and catalysts’ activity were studied. Taking benzene as a model compound, low-temperature ozone catalytic oxidation was conducted to explore the influence of the catalyst carrier, the active metal and the precious metal Pt on the catalytic degradation of benzene. The optimal catalyst appeared to be 0.75%Pt–10%Fe/HZSM(200). The catalytic activity and formation of the by-products methylamine, methanethiol, methanol, dichloroethane and benzene over 0.75%Pt–10%Fe/HZSM(200) were investigated. The structure, oxygen vacancy, surface properties and surface acidity of the catalysts were investigated. XRD, TEM, XPS, H2-TPR, EPR, CO2-TPD, BET, C6H6-TPD and Py-IR were combined to establish the correlation between the surface properties of the catalysts and the degradation activity.

Rich-O-Vacancy WO3/ZrO2–Hβ with High Lewis/Brønsted Ratio: An Efficient Catalyst for the Highly Selective Synthesis of Dipropylene Glycol

“…The signal intensity at 2.003 decreased as follows: 30WO 3 /20ZrO 2 –Hβ > 35WO 3 /20ZrO 2 –Hβ > 25WO 3 /20ZrO 2 –Hβ > 20WO 3 /20ZrO 2 –Hβ > 15WO 3 /20ZrO 2 –Hβ > 20ZrO 2 –Hβ. These results further indicted that 30WO 3 /20ZrO 2 –Hβ has the highest O-vacancy concentration …”

“…These results further indicted that 30WO 3 /20ZrO 2 −Hβ has the highest O-vacancy concentration. 48 Figure 6 shows the Zr 3d, Si 2p, W 4f, and O 1s XPS spectra of xWO 3 /20ZrO 2 −Hβ, and Table 1 lists the surface atomic concentration of O according to XPS analysis. As shown in Figure 6a 26 As listed in Table 1, the ratio of W 5+ / (W 5+ +W 6+ ) (calculated based on the peak area of XPS spectra) was increased from 7.30% to 12.31% as the loading of WO 3 increased from 0 to 30 wt %.…”

Simultaneous Removal of Multipollutants (VOCs/NO/SO2) by Catalytic Ozonation Coupled with Wet Scrubbing Technology: From the Laboratory to Industrial Testing

“…However, in the XRD curve of the Co2.5-Cr1.5 catalyst, the diffraction peak intensity of the Al 2 O 3 structure is weakened, and the diffraction peaks of Cr 2 O 3 and CoO x can hardly be seen, indicating that CoO x has good dispersion on the catalyst surface. After loading CoO x , the relative intensities of all peaks gradually decrease, indicating the enhancement of the metal interaction …”

Catalytic Ozonation of Reactive Red 195 in Aqueous Solution over a Cobalt/Aluminum Oxide-Ceria Catalyst

“…It has been reported that the enhancement of catalytic ozonation involves the adsorption of ozone or pollutant or both of them on the catalyst surface, leading to the formation of free radicals, which react with non-adsorbed species in the bulk liquid. Therefore, the surface characteristics of the catalyst play an important role in the oxidation [32]. Solution pH is one of the most important factors affecting oxide surface properties.…”