Photocatalytic degradation of toluene by platinized titanium dioxide photocatalysts.
A photoreactor has been set up to study the photodegradation of volatile organic compound (VOC) in situ. In the reactor, TiO2 and Pt/TiO2 photocatalysts were immobilized on to UV-transparent quartz support. Scanning electron microscope (SEM) studies and Brunauer-Emmett-Teller (BET) surface area measurements revealed that the quartz fiber support was mostly coated with catalyst with a total surface area of 4.0 +/- 0.3 m2/g. The photocatalytic activity of the photocatalysts was evaluated for the photodegradation of 160 ppm toluene-laden air. It was found that 50-70% of toluene was degraded within the first 5 min of UV illumination. Both TiO2 and Pt/TiO2 photocatalysts suffered from deactivation after 18 hours of continuous operation, and the photocatalysts' activity was significantly reduced. However, platinization doubled the photocatalyst life and delayed the onset of de-activation. The presence of moisture was found to shift the onset of catalyst de-activation to an earlier time. It is concluded that the de-activation of the photocatalyst was due to the accumulation of intermediates on the photocatalysts surface preventing the toluene being adsorbed on the photocatalyst surface for degradation.
Centre for Particle and Catalyst Technologies, School of Chemical Engineering and Industrial Chemistry, The University of New South Wales, Sydney, NSW, 2052, Australia.
C
C
Young
T M
TM
Lim
K
K
Chiang
R
R
Amal
D000393:Air Pollutants / Q000302:isolation & purification*; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry*; D010777:Photochemistry; D010984:Platinum / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014050:Toluene / Q000737:chemistry / Q000302:isolation & purification*
D000393:Air Pollutants; D004396:Coloring Agents; C009495:titanium dioxide; D014050:Toluene; D010984:Platinum; D014025:Titanium