PROCESSING OF CATALYSTS BY ATOMIC LAYER EPITAXY - MODIFICATION OF SUPPORTS

Different supports were modified with titania, zirconia and chromia by the atomic layer epitaxy technique (ALE). In ALE, a metal precursor i s bound to the supper? in saturating gas-solid reactions. Surface oxid es are grown by alternating reactions of the metal precursor and an ox idizing agent. Growth mechanisms differ depending on the precursor-sup port pair and the processing conditions, In this work, the influences of the support, precursor and reaction temperature were investigated b y comparing the growth of titania from Ti(OCH(CH3)(2))(4) on silica an d alumina, titania from TiCl4 and Ti(OCH(CH3)(2))(4) on silica, and zi rconia from ZrCl4 on silica and alumina, The modification of porous ox ides supported on metal substrates (monoliths) was demonstrated for th e growth of chromia from Cr(acac)(3). (C) 1997 Elsevier Science B.V.