Microemulsion-Controlled Synthesis of One-DimensionalIr Nanowires and Their Catalytic Activity in Selective Hydrogenationof o-Chloronitrobenzene.

Ultrathin iridium nanowires havebeen synthesized using a convenientmethod mediated by microemulsion via oriented attachment growth forthe first time. The interconnected polycrystalline Ir nanowires possesshigh aspect ratio, small average diameter of 2 nm, and length up toseveral hundred nanometers. The 1D growth of surfactant-encapsulatedprimary nanoparticles, which is determined by the inherent crystalgrowth habit and the specific interactions of nanocrystals with surfactantmolecules, accounts for the formation of Ir nanowires. The as-preparedIr nanowires show high activity and selectivity toward the hydrogenationproduction of industrially valuable chloroaniline from o-chloronitrobenzene. Theoretical evidence based on DFT calculationindicates that H2could be dissociated more easily andquickly on Ir(100) surface than on Ir(111), accounting for the higherhydrogenation rate over Ir nanowires exposing both (200) and (111)crystal facets rather than only (111) facet for Ir nanoparticles. [ABSTRACT FROM AUTHOR]