Table 3.
Weight percentages of Pt, C, and O of samples processed at varying substrate temperature and hydrogen addition, and at constant pressure (10.5 Pa) and overall carrier gas flow rate (argon and hydrogen gas; 60 sccm) measured by XPS. The degree of oxidation of only the Pt-NPs (mainly Pt(OH)2) of individual samples is shown in parentheses under the Pt weight loading. The platinum loading and degree of oxidation of the whole Pt/CNW catalyst layers are dependent on the substrate temperature and the addition of hydrogen during synthesis.
| Sample/Structure | Temperature [°C] |
Hydrogen addition [sccm] |
Pt [wt%] (Pt0/PtII [%]/[%]) |
C [wt %] |
O [wt %] |
| P10/CNWs | 350 | 0 | 36.1 (86/14) |
60.5 | 3.4 |
| P9/CNWs | 350 | 0.5 | 46.3 (89/11) |
52.2 | 1.5 |
| P8/a-C | 350 | 1 | 68.1 (91/9) |
31.5 | 0.4 |
| P12/CNWs | 500 | 0 | 21.5 (89/11) |
75.5 | 3.0 |
| P11/CNWs | 500 | 0.5 | 28.0 (83/17) |
69.4 | 2.6 |