Palladium-alumina catalysts : a diffuse reflectance study

Abstract

Palladium catalysts are prepared from various precursors (chloride, nitrate, acetylacetonate) by using different methods of precursor bonding on 2 types of alumina. The chemical state and environment of Pd is studied by UV-visible diffuse reflectance spectroscopy along the successive preparation stages. The species formed upon interaction of precursors with the carriers are identified and their transformations upon calcination and reduction are studied. The reactivity of oxide «clusters» towards NH 3 is used as a criterion of their dispersion