Supporting Information

� Wiley-VCH 2009

69451 Weinheim, Germany

High-Index Faceted Platinum Nanocrystals Supported on CarbonBlack as Highly Efficient Catalysts for Ethanol Electrooxidation**Zhi-You Zhou, Zhi-Zhong Huang, De-Jun Chen, Qiang Wang, Na Tian, and Shi-Gang Sun*

anie_200905413_sm_miscellaneous_information.pdf

1. Identification of atomic steps

1.1 Models of different atomic steps

Figure S1. Models of {110}, {210} and {310} atomic steps along <100> crystal zone axis.

Figure S2. Models of {311} and {211} atomic steps along <110> crystal zone axis.

{311} {211}

{110} {210} {310}

CNs=7 CNs=6 CNs=6

CNs=7 CNs=7

Figure S3. Models of {311} and {210} atomic steps along <211> crystal zone axis.

1.2 Assignment of atomic steps of HIF-Pt nanoparticle along <100> crystal zone axis.

Figure S4. Comparison between models of atomic steps and aberration-corrected HRTEM images of one

HIF-Pt nanocrystal along <100> crystal zone axis.

The good agreement between models and real atomic images confirms that the HIF-Pt nanoparticles

contain high density of atomic steps (CNs<8).

2 nm

{310} {210}

{200} {210}

{310}

{110}

{310}

{510

}

{210}

{310}

{510}

{210} {311}

CNs=7 CNs=6

2. In situ FTIR spectroscopic studies of ethanol oxidation

In situ FTIR spectroscopic studies were carried out on a Nicolet 870 FTIR spectrometer equipped

with a liquid-nitrogen-cooled MCT-A detector and an EverGlo IR source. A thin-layer IR cell with a

CaF2 planar window was employed. Infrared radiation sequentially passed through the CaF2 window and

the thin-layer solution, and then was reflected from the electrode surface. The resulting spectra were

reported as relative change in reflectivity, that is, ( ) ( )

(1)( )

S R

R

R E R ER

R R E

−∆=

where R(ES) and R(ER) are the single-beam spectra collected at sample potential (ES) and reference

potential (ER), respectively. As a result, for solution species, downward bands in the resulting spectra

indicate the formation of products, while upward bands denote the consumption of reactants. The spectral

resolution was 8 cm-1

.

2.1 Assignment of species in the FTIR spectra

Table S1 Assignment of IR bands in the spectra for ethanol oxidation in Figure 1

Wavenumbers

/ cm-1

Assignments

[s1] Comments

1044

(upward) ν C−O CH3CH2OH

The other upward band of ethanol at 1086 cm-1

was

swamped by intensive absorption of ClO4- at 1100 cm

-1.

2343 νas Ο=C=O CO2 The final oxidation product generated from the cleavage of

C-C in ethanol.

~ 1720 ν C=O

This band is usually distorted due to the changing of

spectral background (e.g., interference from the H2O

absorption at 1640 cm-1

).

1392 δas CΗ3 /

1370 δs CΗ3

CH3COOH

CH3CHO

/

1280 ν C−O CH3COOH This band is characteristic for acetic acid, and is usually

used for quantitative analysis of acetic acid.

1100 ν ClO4 ClO4-

The increase of ClO4- (diffusion from bulk solution to the

thin-layer solution) is caused by the product of H+ from

ethanol oxidation (e.g., CH3CH2OH + 3H2O à 2CO2 +

12H+ + 12e).

~ 2050 ν CO Adsorbed

CO (COad)

At 0.60 V (SCE), COad can be oxidized quickly. So this

band was originated from reference spectrum (i.e., at

−0.25 V), and may be generated from the dissociative

adsorption of ethanol. In the time-resolved FTIR spectra

collected at 0.60 V (Figure S5), we can observe that this

band is nearly independent on time. The band direction is

reversed due to CO adsorbed on nanomaterials that exhibit

abnormal infrared effects (AIREs).[s2]

2.2 In situ time-resolved FTIR spectra

Figure S5. In situ time-resolved FTIR spectra of ethanol oxidation on HIF-Pt/C and commercial Pt/C at

0.60 V. Time resolution: 10 s; ER= −0.25 V; 0.1 M ethanol + 0.1 M HClO4 solution.

Figure S5 shows the in situ time-resolved FTIR spectra of ethanol oxidation on HIF-Pt/C and

commercial Pt/C at 0.60 V (SCE). The band at ~2050 cm-1

is attributed to linear-bonded CO, and its

intensity is nearly independent on time. At the potential as high as 0.60 V, adsorbed CO (COad) can be

oxidized quickly, so this CO band was originated from the reference spectrum collected at −0.25 V. The

time dependence of IR band intensities of solution species, i.e., CO2 and acetic acid, illustrated clearly

that more CO2 and less acetic acid are produced on the HIF-Pt/C as compared with the commercial Pt/C.

HIF-Pt/C Commercial Pt/C

2400 2000 1600 1200

∆R

/R=

2.0

×10

-2

5 s

15 s

25 s

165 s 155 s

t

ν / cm-1

∼ 2400 2000 1600 1200

∆R

/R=

2.0

×10

-2

t

5 s

15 s

25 s

165 s

155 s

ν / cm-1

∼

CO2 ClO4

−

ClO4−

CO2

COad COad

HAc HAc

Reference

[S1] D. Lin-Vien, N. B. Colthup, W. G. Fateley, J. G. Grasselli, The Handbook of Infrared and Raman

Characteristics Frequencies of Organic Molecules, Academic Press, New York, 1991.

[S2] G.Q. Lu, S.G. Sun, L.R. Cai, S.P. Chen, Z.W. Tian, K.K. Shiu, Langmuir 2000 16, 778.