Table 1.
Summary of XPS data obtained from the surface (<10 nm) of un-reacted and Cr(VI) reacted Pd-BnM.
| Total Cr(VI) removed from solution mg per g−1 Pd-BnM | XPS elemental composition (atomic %) |
XPS |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Fe | Pd | Cr | Na | Si | Ca | Pd metal: Pd oxide | Fe(II): Fe(III) | Cr(III): Cr (VI) | ||
| Pd-BnM unreacted | – | 95 | 5 | 0 | 0 | 0 | 0 | 70: 30 | 29: 71 | – |
| Pd-BnM/formate + Cr(VI) model | 753 ± 38 | 4 | 0 | 50 | 45 | 0 | 0 | – | – | 91: 9 |
| Pd-BnM/H2 + Cr(VI) model | 551 ± 19 | 5 | 0 | 57 | 39 | 0 | 0 | – | – | 90: 10 |
| Pd-BnM/formate + COPR | 30 ± 5 | 13 | 0 | 5 | 0 | 28 | 54 | – | 22: 78 | 100: 0 |
| Pd-BnM/H2 + COPR | 352 ± 32 | 0 | 0 | 7 | 0 | 40 | 53 | – | – | 100: 0 |