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Sonocatalytic degradation of oxalic acid in the presence of oxygen and Pt/TiO2

Paper ID Volume ID Publish Year Pages File Format Full-Text
54486 47011 2015 8 PDF Available
Title
Sonocatalytic degradation of oxalic acid in the presence of oxygen and Pt/TiO2
Abstract

•Oxidation of oxalic acid is enhanced under 360 kHz ultrasound, Pt/TiO2 and oxygen.•OH radicals formed by sonolysis contribute to catalytic activity enhancement.•High frequency ultrasound leads to the highest oxalic acid degradation rate increase.•360 kHz ultrasonic irradiation drastically reduces the average catalyst aggregate size.

In order to treat aqueous effluents containing organic pollutants, several techniques can be considered depending on the organic compound concentration. Sonochemistry appears to be a promising solution to answer water remediation issue. In fact, when submitted into a liquid, ultrasound can induce the nucleation, growth, and violent collapse of vapor/gas filled bubbles. However, despite the extreme local conditions observed during acoustic cavitation, using ultrasound alone is efficient only at low concentration in organic pollutants. In the present study, 0.05 M oxalic acid degradation kinetics were followed at 40 °C under various conditions, in presence or not of Pt/TiO2 catalyst under silent conditions or ultrasound at 20 and 360 kHz. Experiments were achieved under controlled atmosphere and comparison between argon, Ar/O2 (20 vol% O2) and pure O2 conditions was performed. Oxidation rate increase of oxalic acid was measured under Ar/O2 atmosphere in presence of Pt/TiO2 catalyst due to strong dispersion effect of both low and high ultrasonic frequency and formation of chemically active species by sonolysis. High frequency ultrasonic irradiation under Ar/O2 atmosphere gives the highest kinetic increase compared to silent conditions with oxalic acid degradation rate around 13 μmol min−1 at 40 °C with 2 g L−1 of 3 wt% Pt on P25 TiO2 catalyst.

Keywords
Sonochemistry; Catalysis; Ultrasound; Sonocatalysis; Oxalic acid; Oxygen
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Sonocatalytic degradation of oxalic acid in the presence of oxygen and Pt/TiO2
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Publisher
Database: Elsevier - ScienceDirect
Journal: Catalysis Today - Volume 241, Part A, 1 March 2015, Pages 55–62
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us