Conversion characteristics and kinetic analysis of gaseous α-pinene degraded by a VUV light in various reaction media

Photocatalytic conversion of gaseous ethylbenzene on lanthanum-doped titanium dioxide nanotubes

“…Such inhibition at higher humidity was not obvious compared with other photoconversion processes such as ozone-assisted photodegradation and vacuum photodegradation [44,45]. We previously found [46] that for photodegradation of ␣-pinene by vacuum ultraviolet light, a high RH inhibited the generation of ozone, and the conversion decreased. These results were attributed to the competitions between active radicals and organic compounds, which meant that the reaction rate of ·OH and ozone was much faster than that of ·OH and organic compounds or O 3 and organic compounds.…”

Vacuum Ultraviolet Spectroscopy and Mass Spectrometry: A Tandem Detection Approach for Improved Identification of Gas Chromatography-Eluting Compounds

“…For instance, at the shorter wavelength of 125 nm (∼9.9 eV), there is sufficient energy to ionize and potentially photodissociate some molecules; however, detection of intact molecules is possible because of potential ion neutralization and low cross section for photodegradation processes within the VUV cell. In-series VUV-MS detection approach allowed us to confirm that, under our experimental conditions, mass spectra of post-VUV detected analytes (including α-pinene and dichloromethane which are known to photodegrade when exposed to VUV light , ) were not appreciably altered (i.e., by changing the VUV lamp to on or off, the GC peak heights and areas were not affected, and the relative abundances of m / z values and corresponding fragmentation patterns across the GC peak remained constant, see Figure ). Further discussions and additional experimental details/results on this topic are included as Figures S3 and S4.…”

Recent Development of VUV-Based Processes for Air Pollutant Degradation

“…Cheng (Cheng, 2011) investigated the photo-degradation of FIGURE 3 | Time dependences of concentrations of phenol (•), the overall concentrations of 1,2-and 1,4-dihydroxybenzene ( ), the overall concentrations of malic, maleic, and tartaric acids (•); concentrations of oxalic acid ( ), the overall concentrations of the hydroperoxide ( ) and total organic carbon (TOC) concentrations (×) in (A) UV/VUV, and (B) UV-irradiated solutions saturated with oxygen at 1.5 × 10 −3 mol·dm −3 initial concentration (Alapi and Dombi, 2007a).…”

“…Ozone used for ozone-assisted catalytic oxidation was FIGURE 4 | Effect of different humidity on the conversion efficiencies of α-pinene photo-degraded in the air (Cheng, 2011). generally generated from high voltage discharge. The cost of this is high and the system is relatively complex.…”