Cobalt exchanged zeolites for heterogeneous catalytic oxidation of phenol in the presence of peroxymonosulphate

• Published in: Applied catalysis. B, Environmental Vol. 99; no. 1-2; pp. 163 - 169
• Main Authors: Shukla, Pradeep, Wang, Shaobin, Singh, Kailash, Ang, H.M., Tadé, Moses O.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 31.08.2010; Elsevier
• Subjects: Activation; Advanced oxidation; Catalysis; Catalysts; Chemistry; Co catalyst; Cobalt; Degradation; Exact sciences and technology; General and physical chemistry; Ion-exchange; Oxidants; Oxidation; Phenol; Sulphate radical; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Wastewater treatment; Zeolites: preparations and properties; Co catalyst; Phenol; Advanced oxidation; Wastewater treatment; Sulphate radical; Water; Hydrogen peroxide; Alcohol; Activation; Decomposition; Oxidant; Cobalt; Molecular sieve; Degradation; Energy; Oxidation; Catalytic reaction; Cobalt ion; Transition metal; Zeolite; Reaction rate; Heterogeneous catalysis; Phenols; Benzenic compound; Kinetics; Aqueous solution; Waste water purification; Catalyst; Environmental protection
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2010.06.013

High surface area graphites (HSAG) present an improved performance for being used as supports of palladium catalysts for hydrodechlorination reactions. A pertinent activation of the material leads to catalysts more active and resistant to deactivation than other conventional supports. Several cobalt ion-exchanged zeolite catalysts based on ZSM-5, zeolite-A, and zeolite-X were prepared and tested for heterogeneous oxidation of phenol in the presence of various oxidants such as H2O2, persulphate, and peroxymonosulphate. It is found that Co-ZSM-5 is highly effective in heterogeneous activation of peroxymonosulphate to produce sulphate radicals but exhibits low activity for the activation of H2O2 and persulphate for organic oxidation in water. Co-zeolite-A and Co-zeolite-X show much faster reaction rate in homogeneous activation of peroxymonosulphate due to decomposition of the catalysts and leaching of Co ions into aqueous solution. Co-ZSM-5 also presents stable performance in heterogeneous activation of peroxymonosulphate for phenol degradation. The phenol degradation depends on catalyst loading, phenol concentration, oxidant concentration and temperature. Kinetic studies indicate that phenol degradation follows zero-order kinetics with an activated energy of 69.7kJ/mol.