Containing crystalline nanoclusters

To determine the condition of the formation of the carbon-supported Pt nanoclusters, various NaOH concentrations of 3.0 M, 1.0 M, 0.5 M, and 0.1 M were added Into H2PtCl6- and VCB-containing EG solution. Figure 1 shows the powder X-ray diffraction patterns of Pt/CBs, prepared in (a) 3.0 M, (b) 1.0 M, (c) 0.5 M, and (d) 0.1 M NaOH aqueous solutions. All of the samples show typical Pt crystalline peaks of Pt (111), Pt (200), and Pt (220), except for those prepared in 0.1 M concentration. This indicates that the Pt clusters prepared in the 0.1 M NaOH concentration show a rather low loading efficiency. From this result, it was confirmed that the base concentration in the Pt precursor- and carbon-dispersed solutions is a critical factor in the manufacture of carbon-supported Pt nanoclusters. 

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