Gas-phase photocatalytic oxidation of acrylonitrile

Abstract

Photocatalytic oxidation (PCO) of acrylonitrile (AN) on titanium dioxide in the gaseous phase was studied. AN readily undergoes photocatalytic degradation in a gas-solid system by using TiO(2) Degussa P25. The AN PCO volatile products, visible in the infrared spectra, included nitrogen dioxide, nitrous oxide, carbon dioxide, water, hydrogen cyanide and carbon monoxide. Longer contact time resulted in deeper oxidation of AN with decreasing hydrogen cyanide and increasing nitrogen dioxide content. The effect of temperature increasing from 60 to 130 degrees C was observed to be slightly negative in terms of AN degradation rate. However, the effect of increased temperature was noticeable in terms of the character and yields of the PCO products: HCN peaks diminished with growing peaks of NO(2).

A Review of Photocatalysis using Self‐organized TiO2 Nanotubes and Other Ordered Oxide Nanostructures

“…Photocatalytic decomposition was investigated for many types of gaseous pollutants, such as volatile organic compounds (VOCs; see references 223–229), and decomposition frequently follows a Langmuir–Hinshelwood type rate law.…”

Gas-phase Photocatalytic Oxidation of Acrylonitrile on Sulphated TiO2: Continuous Flow and Transient Study

“…The oxidation reaction rates usually depend on temperature increasing with the temperature growth. At the same time adsorption is deteriorated with the temperature increase, compensating the reaction rate improvement having PCO reactions often insensitive towards temperature changes as observed previously with AN PCO at P25 [18]. The 'reaction rate-adsorption' balance at sulphated P25 appears to be dramatically negatively influenced by the temperature decrease practically zeroing its performance.…”

“…The products formed on sulphated TiO 2 differ from the ones formed on Degussa P25 [18] in part of HNCO, the peaks of which appear in the volatile products spectra (Fig. 5).…”

“…The preliminary results of PCO of AN vapours on TiO 2 P25 were described briefly in the recent publication [18]. The present study uses both transient and continuous-flow methods for disclosing the PCO mechanism for AN.…”

Influence of operating parameters on the single-pass photocatalytic removal efficiency of acrylonitrile

“…The PCO of acrylonitrile has not been widely studied in the literature. Krichevskaya et al [42] studied the gas phase degradation of acrylonitrile by using Degussa P25 under UV irradiation at concentrations ranging from 10 to 100 ppm at temperatures ranging from 50 to 130°C. They observed that degradation rates were improved at longer contact times and lower concentrations and decreased at higher temperatures.…”