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Supporting Information Wiley-VCH 2009 69451 Weinheim, Germany High-Index Faceted Platinum Nanocrystals Supported on Carbon Black as Highly Efficient Catalysts

1 Supporting Information Wiley-VCH Weinheim, Germany High-Index Faceted Platinum Nanocrystals Supported on Carbon Black 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_ _sm_miscellaneous_information.pdf

2 1. Identification of atomic steps 1.1 Models of different atomic steps {110} {310} CNs=7 CNs=6 CNs=6 Figure S1. Models of {110}, and {310} atomic steps along <100> crystal zone axis. {311} {211} CNs=7 CNs=7 Figure S2. Models of {311} and {211} atomic steps along <110> crystal zone axis.

nanoparticle along <100> crystal zone axis.

and aberration-corrected HRTEM images of

3 {311} CNs=7 CNs=6 Figure S3. Models of {311} and atomic steps along <211> crystal zone axis. 1.2 Assignment of atomic steps of HIF-Pt nanoparticle along <100> crystal zone axis. {310} {200} {310} {110} {310} {510 } {310} {510} 2 nm 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).

4 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 CaF 2 planar window was employed. Infrared radiation sequentially passed through the CaF 2 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, R R( ES ) R( ER ) = (1) R R( ER ) where R(E S ) and R(E R ) are the single-beam spectra collected at sample potential (E S ) and reference potential (E R ), 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 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 The other upward band of ethanol at 1086 cm -1 was ν C O CH (upward) 3 CH 2 OH swamped by intensive absorption of ClO - 4 at 1100 cm ν as Ο=C=O CO 2 The final oxidation product generated from the cleavage of C-C in ethanol. ~ 1720 ν C=O CH 3 COOH This band is usually distorted due to the changing of spectral background (e.g., interference from the H 2 O absorption at 1640 cm -1 ) δas CΗ 3 CH 3 CHO / 1370 δs CΗ ν C O CH 3 COOH 1100 ν ClO 4 ClO 4 - ~ 2050 ν CO Adsorbed CO (CO ad ) / This band is characteristic for acetic acid, and is usually used for quantitative analysis of acetic acid. The increase of ClO - 4 (diffusion from bulk solution to the thin-layer solution) is caused by the product of H + from ethanol oxidation (e.g., CH 3 CH 2 OH + 3H 2 O 2CO H e). At 0.60 V (SCE), CO ad 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]

5 2.2 In situ time-resolved FTIR spectra HIF-Pt/C Commercial Pt/C 5 s 15 s 25 s 5 s 15 s 25 s R/R= t R/R= t 155 s 155 s 165 s CO ad CO 165 s HAc ad ClO 4 CO CO 2 HAc 2 ClO ν / cm -1 ν / cm -1 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; E R = 0.25 V; 0.1 M ethanol M HClO 4 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 (CO ad ) 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., CO 2 and acetic acid, illustrated clearly that more CO 2 and less acetic acid are produced on the HIF-Pt/C as compared with the commercial Pt/C.

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

SUPPORTING INFORMATION. Direct Observation on Reaction Intermediates and the Role of. Cu Surfaces

SUPPORTING INFORMATION. Direct Observation on Reaction Intermediates and the Role of. Cu Surfaces SUPPORTING INFORMATION Direct Observation on Reaction Intermediates and the Role of Bicarbonate Anions in CO 2 Electrochemical Reduction Reaction on Cu Surfaces Shangqian Zhu, Bei Jiang, Wen-Bin Cai, Minhua