AVS 56th International Symposium & Exhibition
    Surface Science Tuesday Sessions
       Session SS3-TuA

Invited Paper SS3-TuA1
High Catalytic Activity of CeOx/Au(111) and Au/CeOx/TiO2(110): Special Properties of CeOx Nanoparticles

Tuesday, November 10, 2009, 2:00 pm, Room N

Session: Catalysis: Mechanisms & Morphology
Presenter: J.A. Rodriguez, Brookhaven National Laboratory
Authors: J.A. Rodriguez, Brookhaven National Laboratory
J.B. Park, Brookhaven National Laboratory
J. Graciani, Brookhaven National Laboratory
J. Evans, Universidad Central de Venezuela
D.J. Stacchiola, Brookhaven National Laboratory
S.J. Ma, Brookhaven National Laboratory
P.J. Liu, Brookhaven National Laboratory
J. Fdez-Sanz, Universidad de Sevilla, Spain
J. Hrbek, Brookhaven National Laboratory
Correspondent: Click to Email
This talk will focus on a series of studies investigating the catalytic activity of CeOx/Au(111) and Au/CeOx/TiO2(110) for the water-gas shift (WGS, CO + H2O --> H2 + CO2) reaction and CO oxidation. Au(111) is inactive for the WGS. The deposition of ceria nanoparticles on Au(111) produces a highly active WGS catalysts. An even better catalysts is produced after depositing Au and CeOx nanoparticles on TiO2(110). The titania substrate imposes non-typical coordination modes on the ceria nanoparticles. In the CeOx/TiO2(110) systems, the Ce cations adopt an structural geometry and an oxidation state (+3) which are quite different from those seen in bulk ceria or for ceria nanoparticles deposited on metal substrates. The increase in the stability of the Ce3+ oxidation state leads to an enhancement in the chemical and catalytic activity of the ceria nanoparticles. The co-deposition of ceria and gold nanoparticles on a TiO2(110) substrate generates catalysts with an extremely high activity for the production of hydrogen through the WGS or for the oxidation of carbon monoxide. The exploration of mixed-metal oxides at the nanometer level may open new avenues for optimizing catalysts through stabilization of unconventional surface structures with special chemical activity.