Efficient photocatalytic degradation of organics present in gas and liquid phases using Pt-TiO2/Zeolite (H-ZSM)

• Total catalytic oxidation of organics present in liquid and gas phases within a short period of time.
• Dark reaction takes place with Pt-TiO2-H-ZSM.
• No residual organics present in the pores of zeolites.
• Overcome the problems of strong adsorption of organics (unreacted) in the pores of zeolites and make the catalysts active for consecutive runs.
• Pt-TiO2-H-ZSM is the best catalyst for liquid phase oxidation.

TiO2-encapsulated H-ZSM photocatalysts were prepared by physical mixing of TiO2 and zeolites. Pt was immobilized on the surface of the TiO2-encapsulated zeolite (H-ZSM) catalysts by a simple photochemical reduction method. Different weight ratios of both TiO2 and Pt were hybridized with H-ZSM and the catalytic performance of the prepared catalysts was investigated for 2-propanol oxidation in liquid phase and acetaldehyde in gas phase reaction. Around 5–10 wt% TiO2-encapsulated H-ZSM catalysts was found to be optimal amount for the effective oxidation of the organics. Prior to light irradiation, Pt-TiO2-H-ZSM showed considerable amount of catalytic degradation of 2-propanol in the dark, forming acetone as an intermediate. In this study, Pt has played a major and important role on the total oxidation of 2-propanol as well as acetaldehyde. As a result, no residual organics were present in the pores of the zeolites. The catalysts could be reused more than three times without losing their catalytic activity in both phases. The Pt-TiO2-H-ZSM photocatalysts could overcome the problem of strong adsorption of organics in the zeolite pores (after the reaction). Thus, Pt-TiO2-H-ZSM can be used as a potential catalyst for both liquid and gas phase oxidation of organic pollutants.

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