title: Silica-supported Au nanoparticles decorated by TiO2: formation, morphology, and CO oxidation activity.
abstract: Au-TiO(2) interface on silica support was aimed to be produced in a controlled way by use of Au hydrosol. In method A, the Au colloids were modified by hydrolysis of the water-soluble Ti(IV) bis(ammoniumlactato)dihydroxide (TALH) precursor and then adsorbed on Aerosil SiO(2) surface. In method B, Au sol was first deposited onto the SiO(2) surface and then TALH was adsorbed on it. Regular and high-resolution transmission electron microscopy (TEM and HRTEM) and energy dispersive spectrometry (EDS) analysis allowed us to conclude that, in method A, gold particles were able to retain the precursor of TiO(2) at 1.5 wt % TiO(2) loading, but at 4 wt % TiO(2) content the promoter oxide appeared over the silica surface as well. With method B, titania was detected on silica at each TiO(2) concentration. In Au-TiO(2)/SiO(2) samples, the stability of Au particles against sintering was much higher than in Au/TiO(2). The formation of an active Au-TiO(2) perimeter was proven by the greatly increased CO oxidation activity compared to that of the reference Au/SiO(2).
authors.affiliation: Department of Surface Chemistry and Catalysis and Radiation Safety Department, Institute of Isotopes, Hungarian Academy of Sciences, Post Office Box 77, H-1525 Budapest, Hungary. ahorvathy@sunserv.kfki.hu
authors.forename: Anita
authors.initials: A
authors.lastname: Horváth
authors.forename: Andrea
authors.initials: A
authors.lastname: Beck
authors.forename: Antal
authors.initials: A
authors.lastname: Sárkány
authors.forename: Györgyi
authors.initials: G
authors.lastname: Stefler
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Varga
authors.forename: Olga
authors.initials: O
authors.lastname: Geszti
authors.forename: Lajos
authors.initials: L
authors.lastname: Tóth
authors.forename: László
authors.initials: L
authors.lastname: Guczi