Physicochemical characteristics and CO oxidation over Pd/(α- Fe₂O₃ +SnO₂) catalyst

Abstract

<i>a</i>-Fe₂O₃,+ SnO₂, catalyst prepared by coprecipitation method has been investigated for its calcination and hydrogen reduction behaviour. There is no chemical reaction between <i>a</i>-Fe₂O₃, and SnO₂ upto a calcination temperature of 1175 K and <i>a</i>-Fe₂O₃ has remained amorphous upto 775 K as revealed by X-ray diffraction and Mössbauer spectroscopy. Results of catalytic oxidation of CO carried out using pulse method on the mixed oxide and individual oxide systems suggest no synergistic effects between <i>a</i>-Fe₂O₃; and SnO₂. The impregnation of Pd metal over the mixed oxide catalyst has facilitated CO oxidation. CO disproportionation has been observed over palladium sites in the temperature range 350 to 400 K. The conversion of α-Fe₂O₃, to <img src='/image/spc_char/gamma2.gif' border=0>-Fe₂-O₃, in Pd/(Fe₂O₃ + SnO₂) catalyst is found to enhance its activity for CO oxidation.