title: Tuning of catalytic CO oxidation by changing composition of Rh-Pt bimetallic nanoparticles.
abstract: Recent breakthroughs in synthesis in nanoscience have achieved control of size and composition of nanoparticles that are relevant for catalyst design. Here, we show that the catalytic activity of CO oxidation by Rh/Pt bimetallic nanoparticles can be changed by varying the composition at a constant size (9+/-1 nm). Two-dimensional Rh/Pt bimetallic nanoparticle arrays were formed on a silicon surface via the Langmuir-Blodgett technique. Composition analysis with X-ray photoelectron spectroscopy agrees with the reaction stoichiometry of Rh/(Pt+Rh). CO oxidation rates that exhibit a 20-fold increase from pure Pt to pure Rh show a nonlinear increase with surface composition of the bimetallic nanoparticles that is consistent with the surface segregation of Pt. The results demonstrate the possibility of controlling catalytic activity in metal nanoparticle-oxide systems via tuning the composition of nanoparticles with potential applications for nanoscale design of industrial catalysts.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Jeong Young
authors.initials: JY
authors.lastname: Park
authors.forename: Yawen
authors.initials: Y
authors.lastname: Zhang
authors.forename: Michael
authors.initials: M
authors.lastname: Grass
authors.forename: Tianfu
authors.initials: T
authors.lastname: Zhang
authors.forename: Gabor A
authors.initials: GA
authors.lastname: Somorjai
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry* / Q000302:isolation & purification; D002384:Catalysis; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008670:Metals / Q000737:chemistry; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D008670:Metals; D002245:Carbon Dioxide; D010984:Platinum; D012238:Rhodium