Preparation and catalytic activity of K4Zr5O12 for the oxidation of soot from vehicle engine emissions

Abstract

Pure phase K4Zr5O12 is synthesized via solid state method in the present work. Various K/Zr ratios and temperatures are applied, and the synthesis process is investigated in detail by means of X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. Its catalytic activity for soot oxidation is studied by temperature programmed oxidation with different types of soot/catalyst contacts. It is revealed that K4Zr5O12 is very active in the presence of 2-10% O-2 for both tight and loose contacts (T-p(tight) = 335 degrees C, T-p(ethanol) = 355 degrees C and T-p(shaking) = 370 degrees C). Thermal stability study shows that K4Zr5O12 is highly stable up to at least 900 degrees C. (C) 2010 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.