Kétdimenzios modellkatalizâtorok tanuhnânyozasa pâsztâzô alagutmikroszkopiâval

Translated title of the contribution: 2D model catalysts studied by scanning tunneling microscopyRh, Ir supported on TiO2(110)-(1x2)

Berkö Andres, Solymosi Frigyes

Research output: Contribution to journalArticle

Abstract

Preparation and properties of noble metal clusters (Rh, Ir) on TiO2(110)-(1x2) surface are studied by scanning tunneling microscopy and spectroscopy. Formation of 12 nm of 3D clusters begins already at 300 K for 1 % monolayer (ML) noble metal coverage. The terrace edges are not preferred centres in this case. By enhancement of the deposited metal up to 1-2 ML the cluster size increases above 5 nm. The effect of annealing below 700 K results in a moderate increase of the cluster size. Above 900 K, however, the metal clusters agglomerate and collapse resulting in separated larger crystallites, which are bonded mainly at the crosspoints of terrace edges. By exploiting the large difference in the diffusion coefficient between noble metal atoms and crystallites larger than 1-2 nm, we suggest a method (called "seeding + growing") by which an independent control of average cluster size and interparticle distance is attainable. The applicability of this method in the studies of some important processes (cluster size dependence of the treatments in different gases, decoration phenomena, etc.) in the field of heterogeneous catalysis are demonstrated in this work.

Original languageHungarian
Pages (from-to)7-20
Number of pages14
JournalMagyar Kemiai Folyoirat, Kemiai Kozlemenyek
Volume106
Issue number1
Publication statusPublished - Dec 1 2000

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ASJC Scopus subject areas

  • Chemistry(all)

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