Role of oxygen storage/supply capacity of mixed oxides of Ce and Zr in ethanol oxidation

A series of CexZr1-xO2 (x = 0.25, 0.5, 0.75) was prepared by precipitation method and wet impregnation method was employed for the synthesis of Au/CexZr1-xO2 catalysts. All prepared catalysts were characterized by XRD, TEM, EDX, TGA, and FTIR spectroscopy. Catalytic activity was studied in the temperature range of 200-350 degrees C and total pressure of 5 atm maintaining GHSV of 18,000 mLg(cat) (-1) h(-1) for oxidation of ethanol (aqueous solution with a typical concentration in bioethanol, i.e., 10 wt%). Results showed that insertion of Zr to Ce framework improved the oxygen storage capacity (OSC) which subsequently enhances supply of oxygen for the reaction and ultimately leading to increased ethanol conversion. Increased Zr content in Ce framework led to enhance ethanol conversion, while reverse trend was observed for acetaldehyde selectivity. Au/CexZr1-xO2 catalysts exhibited good catalytic behavior in terms of conversion and selectivity towards acetaldehyde and displayed time-on-stream. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.