Wet oxidation of phenolic solutions over heterogeneous catalysts: Degradation profile and catalyst behavior

• Published in: Journal of catalysis 1998-07, Vol.177 (2), p.247-258
• Main Authors: Hamoudi, Safia, Larachi, Faïçal, Sayari, Abdelhamid
• Format: Article
• Language: English
• Subjects: Catalysis; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1006/jcat.1998.2125

Removal of phenol by wet air oxidation (WAO) from dilute aqueous solutions was conducted in the presence of oxygen over a 1 wt% Pt/Al 2O 3 and Mn/Ce (7/3) composite oxide catalysts. The reaction was carried out in a batch slurry reactor using pure oxygen as an oxidizing agent under mild reaction conditions, i.e., temperature from 80 to 175°C and oxygen pressure from 0.5 to 1.5 MPa. The platinum catalyst was found to be moderately active, while the Mn/Ce catalyst was remarkably effective in reducing both phenol concentration and total organic carbon. On both catalysts the kinetics of phenol removal was characterized by a fast reaction step followed by a slower one. During WAO reaction, a carbonaceous material was formed and deposited on the catalysts surface. This deposit was characterized by temperature-programmed oxidation coupled to mass spectrometry detection and X-ray photoelectron spectroscopy.