Supplementary Material

Figure S1. XRD patterns of (a) SnO2, (b) 3Au/SnO2, (c) Pt-3Au/SnO2, and (d) Pd-3Au/SnO2.

Figure S2. XRD patterns of yAu/SnO2 (y = 0-5.0 wt%) catalysts at (a) y = 0, (b) y = 1.0, (c) y = 2.0, (d) y = 3.0, (e) y = 4.0, and (f) y = 5.0.

Figure S3. Au 4f XPS spectra of (a) 3Au/SnO2 and (b) CO-pretreated 3Au/SnO2.

Figure S4. Pd 3d and Au 4f XPS spectra of Pd/SnO2, 3Au/SnO2, and Pd-3Au/SnO2 catalysts.

Figure S5. Pt 4f and Au 4f XPS spectra of Pt/SnO2, 3Au/SnO2, and Pt-3Au/SnO2 catalysts.

Table S1. Surface areas and mean Au particle sizes of the yAu/SnO2 catalysts

y (wt%) / BET surface area (m2/g) / Gold particle size a (nm)
0.0 / 83.2 / -
1.0 / 87.1 / 6.2
2.0 / 89.2 / 9.0
3.0 / 87.3 / 14.2
4.0 / 82.4 / 19.3
5.0 / 81.4 / 25.5

a The average particle size of Au in yAu/SnO2 was calculated from the XRD data of Au (200) peak according to the Scherrer’s equation.

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Table S2. Binding energies of the Pd 3d, Pt 4f, Au 4f, and Sn 3d of the catalysts

Catalyst / Pd 3d / Pt 4f / Au 4f / Sn 3d
Pd3d3/2 / Pd3d5/2 / Pt 4f5/2 / Pt4f7/2 / Au 4f5/2 / Au 4f7/2 / Sn 3d5/2
Pd/SnO2 / 336.4 / 341.8 / - / - / - / - / 487.5
Pd-3Au/SnO2 / 336.4 / 341.8 / - / - / 88.1 / 91.7 / 487.8
Pt/SnO2 / - / - / 71.4 / 74.8 / - / - / 487.3
Pt-3Au/SnO2 / - / - / 71.15 / 74.55 / 88.4 / 92.05 / 487.7
3Au/SnO2 / - / - / - / - / 88.6 / 92.2 / 487.2

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