Supporting Information

Supporting Information

Microemulsion-Controlled Synthesis of One-Dimensional Ir

Nanowires and Their Catalytic Activity in Selective Hydrogenation of

o-Chloronitrobenzene

Ting Lu, Haisheng Wei, Xiaofeng Yang, Jun Li, Xiaodong Wang and Tao Zhang

Characterization

The X-ray diffraction (XRD) patterns were recorded with a PANalytical X’Pert-Pro powder X-ray diffractometer, using Cu Kα monochromatized radiation (λ = 0.1541 nm) at a scan speed of 5°/min.

Adsorption of N2 was performed on a Micromeritics ASAP 2460 automated adsorption system to obtain the BET surface area.

HAADF-STEM images were recorded on a JEOL2010F instrument by an electron probe (0.5 nm diameter) at a diffraction camera length of 10 cm. HRTEM image was recorded on the same microscope with 0.19 nm spatial resolution.

Dynamic Light Scattering (DLS) measurements were performed with a spectrometer (ALV-5000/E/WIN Multiple Tau Digital Correlator) with a Spectra-Physics2017 200 mW Ar laser (632.8 nm wavelength). Prior to measurement, the sample was filtered through a 0.22 μm membrane of hydrophilic PVDF filter into light scattering cells to make sure dust-free solution. The scattering angle was

of CONTIN.

Small angle X-ray scattering (SAXS) experiment was completed with a high-flux SAXS instrument (SAXSess mc2, Anton Paar) equipped with a Kratky collimation system and an imaging plate (IP) as the detector. The IP with a pixel size of 43×43 μm2 covers both the small-angle range and the wide-angle range (the q range is up to 28 nm-1, q = (4πsinθ)/λ, where the λ is the wavelength of 0.1542 nm and 2θ is the scattering angle). The liquid sample for SAXS measurement was carefully loaded into a quartz capillary with a diameter of 1 mm. The scattering profile was recorded at 60 ºC after equilibrating for 10 min. The test lasted 30 min to get good signal-to-noise ratio. The pair-distance distribution function (PDDF) was calculated from the scattering curve using the generalized indirect Fourier transform (GIFT)1-3 program included in the SAXSess mc2 software package.

Geometry optimizations and transition state searches were performed at the level of relativistic density functional theory (DFT) using projector augmented wave (PAW) method in Vienna ab-initio simulation package (VASP) with a kinetic energy cut-off of 400 eV.4-9 Ir(111) and Ir(100) surfaces were modeled using a four-layer slabs inside a 3×3 periodic unit cell that is separated from its neighboring images by a 15 Å-width vacuum in the direction perpendicular to the surface. Two-dimensional

surface were optimized while the other two layers beneath the surface were frozen during the geometry optimizations till the residual forces were less than 0.02 eV/Å. The transition states were obtained by relaxing the force below 0.05 eV/Å by the CI-NEB method.11

Figure S1. Schematic illustration of oriented aggregation mechanism for reverse

microemulsion-based synthesis of Ir nanowires.

Figure S2. TEM images of the products with different reaction times: (a) reduction

moment and (b) 90 min via CTAB microemulsion system at 60 oC.

Figure S3. TEM images of as-synthesized Ir nanowires via CTAB microemulsion

system with different CTAB concentration: (a) 1.0 g and (b,c) 0.1 g.

Figure S4. Chemical structures and corresponding abbreviations of various

surfactants used in the microemulsions.

N Br O S O O O Na N Br N Br (OCH₂CH₂)₄OH (f) SDS (e) Brij30 (c) DTAB (a) CTAB (g) 16-2-16 (b) CEAB N N Br Br (OCH₂CH₂)₁₀OH (d) TX-100

a

b

c

Figure S5. TEM images of Ir nanowires via reverse microemulsion systems with

different surfactants at 40 o_{C: (a) CTAB, (b) DTAB, (c) CTAB and Brij30 (molar ratio} of 1/1), (d) CTAB and TX-100 (molar ratio of 1/1), (e) CTAB and SDS (molar ratio of 2/1), (f) Brij30.

a

b

e

_f

Figure S6. Representative TEM (a), HAADF-STAM (b) images and XRD parttern (c)

of as-synthesized Ir nanowires via 16-2-16 microemulsion at 60 oC.

30 40 50 60 70 80 90 In te nsit y ( a.u.) 2degree) (222) (311) (220) (111) (200)

b

a

c

₊

Figure S8. TEM micrographs and diameter distribution for Ir nanowires prepared by

CTAB microemulsion at different temperatures: (a) 40 oC, (b) 80 oC.

Figure S9. SEM image of Ir powder on sale.

Figure S10. Schematic illustration of H2 dissociation on Ir(111) and Ir(100) crystal facets. 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 0 20 40 60 80 100 _{dmean = 1.80 ±0.13 nm} Nu m be r o f pa rtic les Diameter (nm)

a

b

Ir(111)

H

(g)

Ir(100)

Figure S11. N2 adsorption/desesorption isotherms of Ir nanowires (Figure 1a sample) and Ir nanoparticles (Figure S3b sample).

References

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(5) Kresse, G.; Hafner, J. Ab Initio Molecular-dynamics Simulation of the Liquid-metal amorphous-semiconductor Transition in Germanium. Phys. Rev. B. 1994, 49, 14251–14269.

(6) Kresse, G.; Furthmuller, J. Efficiency of Ab-initio Total Energy Calculations for Metals and Semiconductors using A Plane-wave Basis Set. Comput. Mater. Sci. 1996, 6, 15–50.

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0.0 0.2 0.4 0.6 0.8 1.0 0 20 40 60 80 100 120 140 Qu anti ty a ds orbed ( cm 3 /g S T P ) Relative pressure (_P/P0) Ir nanowires Ir nanoparticles