INFLUENCE OF THE PREPARATION PROCEDURE ON THE CHEMICAL AND MICROSTRUCTURAL PROPERTIES OF LANTHANA PROMOTED RH SIO2 CATALYSTS - A FTIR SPECTROSCOPIC STUDY OF CHEMISORBED CO/

In this work, the influence of the preparation procedure on the chemic al and microstructural properties of a series of Rh/La2O3/SiO2 catalys ts has been investigated. The catalysts were characterized by using HR EM, H-2 and CO volumetric adsorption and FTIR spectroscopy of chemisor bed CO. From our study, significant effects were observed for the foll owing preparative variables: (a) the lanthana loading; (b) the way of introducing the metal and promoter, either consecutive (lanthana first and then the rhodium salt) or by co-impregnation; and (c) the calcina tion temperature (873 K or 1173 K) applied for preparing the La2O3/SiO 2 intermediate phase onto which the noble metal was deposited.