In Situ Studies on Photocatalytic Materials, Surface Intermediates, and Reaction Mechanisms

In Situ Studies on Photocatalytic Materials, Surface Intermediates, and Reaction Mechanisms 

Heterogeneous Catalysts for Clean Technology Spectroscopy, Desi, and Monitoring, First Edition. 

In situ FTIR and diffuse reflectance infrared Fourier transform spectroscopic (DRIFTS) studies deal mainly with photocatalytic oxidation or reduction of nitric oxide (NO) as important pollutant and green house gas as well as the depollution or selective oxidation of organics such as olefinic, aliphatic, aromatic, and oxygenated hydrocarbons. 

The photocatalytic reduction of NO was also studied by in situ FTIR on a PtO PdOj,/Ti02 photocatalyst [23]. A special monoHthic multichannel reactor with coated catalysts was used. The catalysts were iUuminated directly in the channels 

The NO/propane/02 and NO/propane/HjO systems showed an opposite trend. Oxygen and water significantly inhibited the reduction of NO because oxygen competed with NO as oxidant, while water interfered with the adsorption of both NO and propane. Ti02 became superhydrophilic under UV light and as a result the catalyst adsorbed water even at low partial pressure, which blocked the active sites. 

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