title: Metal-organic framework-immobilized polyhedral metal nanocrystals: reduction at solid-gas interface, metal segregation, core-shell structure, and high catalytic activity.
abstract: For the first time, this work presents surfactant-free monometallic and bimetallic polyhedral metal nanocrystals (MNCs) immobilized to a metal-organic framework (MIL-101) by CO-directed reduction of metal precursors at the solid-gas interface. With this novel method, Pt cubes and Pd tetrahedra were formed by CO preferential bindings on their (100) and (111) facets, respectively. PtPd bimetallic nanocrystals showed metal segregation, leading to Pd-rich core and Pt-rich shell. Core-shell Pt@Pd nanocrystals were immobilized to MIL-101 by seed-mediated two-step reduction, representing the first example of core-shell MNCs formed using only gas-phase reducing agents. These MOF-supported MNCs exhibited high catalytic activities for CO oxidation.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST) , Ikeda, Osaka 563-8577, Japan.
authors.forename: Arshad
authors.initials: A
authors.lastname: Aijaz
authors.forename: Tomoki
authors.initials: T
authors.lastname: Akita
authors.forename: Nobuko
authors.initials: N
authors.lastname: Tsumori
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D002384:Catalysis; D005740:Gases / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D005740:Gases; D009942:Organometallic Compounds; D002245:Carbon Dioxide; D010984:Platinum; D010165:Palladium