Photocatalytic NOx abatement: The effect of high air flow velocity

0559887 - ÚFCH JH 2023 RIV NL eng J - Journal Article
Mikysková, Eliška - Martiniaková, Ivana - Žouželka, Radek - Rathouský, Jiří
Photocatalytic NOx abatement: The effect of high air flow velocity.
Environmental Technology & Innovation. Roč. 28, NOV 2022 (2022), č. článku 102820. ISSN 2352-1864. E-ISSN 2352-1864
R&D Projects: GA MPO(CZ) FV40209; GA ČR(CZ) GA19-12109S; GA MŠMT(CZ) LM2018124; GA MŠMT(CZ) EF16_013/0001821
Grant - others:GA MŠk(CZ) CZ.02.1.01/0.0/0.0/16_013/0001821; AV ČR(CZ) StrategieAV21/23
Program: StrategieAV
Institutional support: RVO:61388955
Keywords : photocatalysis * TiO2 * NOx abatement
OECD category: Physical chemistry
Impact factor: 7.1, year: 2022
Method of publishing: Open access

In the literature, the abatement of nitrogen oxide (NO) emissions by photocatalysis is rarely carried out at real-world air flow velocities. Here, we investigated the performance of two commercial photocatalysts, Aeroxide® TiO 2 P25 (Evonik Industries, Germany) and FN NANO®2 (Advanced Materials-JTJ, Czech Republic), P25 containing 88 % anatase and 12 % rutile, while FN 2 moreover 13 % of a binder. The degradation of NOx pollutants (0.1 and 1.0 ppmv) at air flow velocities ranging from 0.02 to 0.7 m s was tested, the photocatalytic efficiency being determined for various slit heights (5–25 mm) and rate of volume flow (1500–11 000 cm 3 min). The photocatalysts achieved substantial NO and NO abatement. Pollutant conversion decreased as the air flow velocity increased, with the highest conversion (80%) occurring at 0.1 m s. The NO conversions were slightly higher for NO than for NO2, and significantly higher for the NO concentration of 0.1 ppmv. Slit height had a negligible effect, indicating a substantial degree of mixing in the direction perpendicular to the flow. Consequently, the flow cannot be laminar in nature as the ISO standard (22197-1:2016) states. This finding is supported by the nanoindentation technique showing that the surface roughness contributed to the formation of vortexes and enhancement of the mass transport. To our best knowledge, this is the first study to test commercial photocatalysts under such a wide range of air velocities and, in doing so, it has identified considerable implications for outdoor air purification.
Permanent Link: https://hdl.handle.net/11104/0333014