Supporting Information

Olefin hydrogenation catalysis of platinum nanocrystals with different shapes

Ming Cao, Keiko Miyabayashi,Zhongrong Shen, Kohki Ebitani, Mikio Miyake*

School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1, Asahidai, Nomi-shi, Ishikawa 923-1292, Japan.

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Calculation of Turnover frequency (TOF) values for Pt nanocrystals

To quantify TOF, the amounts of the surface atoms are calculated for the different Pt nanocrystals used in the present study (Table S1). Pt cube is 6.7 nm, composed entirely of (100) facet (calculated using cube model). Pt tetrahedron is 4.6 nm, composed entirely of (111) facet (calculated using the tetrahedron model).Pt cuboctahedron (7.5nm)is formed with (100) and (111) facets, whichis assumed to follow a cuboctahedron structure model.The cylinder is used as model for Pt nanowire (diameter 2nm, length 50nm), which is composed of entire (111) facet.

The assuming average Pt surface densities are of 1.31019 atomsm-2and 1.51019 atomsm-2for Pt(100) and Pt(111) facets, respectively(Anderson 1975).[1]For each shape, formulae for the calculation of the total atoms, the number of surface atoms could be obtained, which depended on the size of the Pt nanocrystals by TEM.

Table S1The surface area, volume and the number of surface atoms of a Pt nanocrystal according to the ideal model

size (nm)* / Surface area
(one particle)
(nm2) / Volume
(one particle)
(nm3) / The number of surface atoms(one particle)
(atoms)
Pt cube / a=6.7 / 269.3 / 300.8 / 3.51021
Pt tetrahedron / a=4.6 / 36.6 / 11.5 / 5.51020
Pt cuboctahedron / a=7.5 / 133.1 / 124.3 / 1.91021
Pt nanowire / a=2.0; L=50 / 314.2 / 157.1 / 4.71021

* a: length of edge for Pt cube and Pt tetrahedron, or diameter of Pt cuboctahedron and Pt nanowire;L: length of cylinder for Pt nanowire.

Fig. S11HNMR of Pt nanowire with PAA.

Fig. S2 Shape distributions of Pt nanocrystals. (a) Pt cube (10.1 nm), (b) Pt cube (9.5 nm), (c) Pt cube (8.2 nm), (d) Pt cube (6.7 nm), (e) Pt tetrahedron (4.6 nm) and (f) Pt cube (8.5 nm) after 3rd hydrogenation of cyclohexene.

Fig. S3 Size distributions of Pt nanocrystals. (a) Pt cube (10.10.7 nm), (b) Pt cube (9.50.8 nm),(c) Pt cube (8.20.5 nm), (d) Pt cube (6.70.6 nm), (e) Pt tetrahedron (4.61.2 nm), (f) Pt nanowire (2.0 nm), (g) Pt cuboctahedron (7.50.5 nm) and (h) Pt cube (8.50.7 nm) after 3rd hydrogenation of cyclohexene.

Fig. S4XPS spectra (Pt 4f) of (a) Pt cube (6.7 nm), (b) Pt tetrahedron (4.6 nm),

(c) Pt nanowire (2.0 nm)and (d) Pt cuboctahedron (7.5 nm).

Table S2Binding energies of Pt 4f of Pt cube, Pt tetrahedron, Pt nanowire and Pt cuboctahedron

Pt 4f5/2 (eV) / Pt 4f7/2 (eV) / Pt(x+) content
Pt(x+) / Pt(0) / Pt(x+) / Pt(0)
Pt cube (6.7 nm) / 75.5 / 74.3 / 72.2 / 71.0 / 12.8%
Pt tetrahedron (4.6 nm) / 75.4 / 74.3 / 72.2 / 71.0 / 17.2%
Pt nanowire (2.0 nm) / 75.5 / 74.4 / 72.2 / 71.1 / 19.4%
Pt cuboctahedron (7.5 nm) / 75.5 / 74.4 / 72.3 / 71.1 / 16.8%

1

1. Anderson JR (1975) Structure of Metallic Catalysts, Academic Press, London.