Manganese functionalized silicate nanoparticles as a Fenton-type catalyst for water purification by Advanced Oxidation Processes (AOP)

Abstract

Wet hydrogen peroxide catalytic oxidation (WHPCO) is one of the most important industrially applicable advanced oxidation processes (AOPs) for the decomposition of organic pollutants in water. It is demonstrated that manganese functionalized silicate nanoparticles with interparticle porosity act as a superior Fenton-type nanocatalyst in WHPCO as they can decompose 80% of a test organic compound in 30 minutes at neutral pH and room temperature. By using X-ray absorption spectroscopic techniques it is also shown that the superior activity of the nanocatalyst can be attributed uniquely to framework manganese, which decomposes H 2O 2 to reactive hydroxyls and, unlike manganese in Mn 3O 4 or Mn 2O 3 nanoparticles, does not promote the simultaneous decomposition of hydrogen peroxide. The presented material thus introduces a new family of Fenton nanocatalysts, which are environmentally friendly, cost-effective, and possess superior efficiency for the decomposition of H 2O 2 to reactive hydroxyls (AOP), which in turn readily decompose organic pollutants dissolved in water. Manganese functionalized silicate nanoparticles with interparticle porosity act as a superior Fenton-type nanocatalyst in WHPCO (wet hydrogen peroxide catalytic oxidation) as they can decompose 80% of a test organic compound in 30 minutes at neutral pH and room temperature. By combined use of catalytic tests and X-ray absorption spectroscopic techniques (XANES, EXAFS) direct evidence is given that the superior activity of the nanocatalyst is uniquely attributed to framework manganese. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.