Table 1.
Sample | Metal contenta (wt%) | Au:Pd (atomic ratio) | Dmetalf (nm) | a0g (nm) | SBET (m2 g−1) | Vt (cm3 g−1) | Dp (nm) | ||||
---|---|---|---|---|---|---|---|---|---|---|---|
Au | Pd | Theo.b | XPSc | EDX-TEMd | EDX-STEMe | ||||||
Au | 3.25 | 0 | - | - | - | - | 3.1 | 0.4062 | 359 | 0.24 | 3.6 |
Au80Pd20 | 2.90 | 0.39 | 4 | 4.18 | 3.88 | n.p.h | 3.2 | 0.4042 | 329 | 0.23 | 3.7 |
Au67Pd33 | 2.58 | 0.65 | 2 | 1.80 | 1.86 | 1.79 | 2.7 | 0.4022 | 334 | 0.23 | 3.6 |
Au50Pd50 | 2.12 | 1.17 | 1 | 0.90 | 0.92 | 1.10 | 2.9 | 0.4017 | 359 | 0.24 | 3.6 |
Au33Pd67 | 1.58 | 1.71 | 0.5 | 0.42 | 0.52 | 0.48 | 3.2 | 0.3991 | 336 | 0.23 | 3.6 |
Au20Pd80 | 1.03 | 2.25 | 0.25 | 0.21 | 0.22 | n.p. | 3.2 | 0.3980 | 315 | 0.22 | 3.6 |
Pd | 0 | 3.31 | - | - | - | - | 2.8 | 0.3901 | 348 | 0.23 | 3.6 |
Au50Pd50-R6i | 2.12 | 1.17 | 1 | 0.92 | 0.90 | 1.08 | 2.9 | 0.4017 | 292 | 0.18 | 3.4 |
For comparison, the properties for monometallic Au and Pd catalysts are also provided
aTheoretical Au and Pd contents
bTheoretical Au:Pd atomic ratio
cAu:Pd atomic ratio estimated from the XPS spectra
dAu:Pd atomic ratio estimated from the EDX pattern collected in TEM mode
eAu:Pd atomic ratio estimated from EDX with a focused electron beam in the sub-nanometre range in STEM mode
fParticle size estimated from the TEM images of the monometallic gold, monometallic palladium or nanoalloy AuxPdy
gLattice spacing of metal calculated from the wide-angle XRD pattern
hn.p.: not provided
iThe Au50Pd50 catalyst after the sixth catalytic run