(a) TEM of DDA/TOPB-capped Pd MNPs. (b) TEM of DDA/DDAB-capped Pd MNPs. (c) XAFS raw data of the three Pd MNPs and bulk Pd at the Pd -edges.
(a) The S -edge XANES of PdSR and a free thiol reference. (b) The Pd -edge EXAFS of Pd, PdSR, and bulk Pd. (c) The Pd -edge XANES and (d) the Pd -edge XANES of Pd and PdSR.
(a) The Pd -edge EXAFS, (b) the Pd -edge, and (c) -edge XANES of Pd, Pd, and bulk Pd.
The Pd -edge XANES of Pd, Pd, and bulk Pd.
(a) Average spectra and (b) site-specific spectra of FEFF8 simulated Pd -edge XANES of various Pd cluster models. The model schematically shown in (a) is a cluster and in (b) is part of the cluster viewed from and directions, respectively. The white line maximum positions of the average spectra of different clusters are also marked in (a) with short bars perpendicular to the arrow near the white lines.
XPS valence-band spectra of the three Pd MNPs and bulk Pd. The bandwidth values are given in the figure.
XPS core-level spectra of the three Pd MNPs and the bulk. (a) The original spectra. (b) A comparison of the line shape of the two weakly bound MNPs and bulk Pd by aligning the peaks of the MNPs with that of the bulk. (c) A line shape comparison of Pd and PdSR by aligning the peak of PdSR with that of Pd.
(a) TEM of the 75% Pd alloy nanoparticles, (b) the Pd -edge, (c) and the -edge XANES of Pd, bulk Pd, and alloy MNPs. (d) FEFF-simulated Pd -edge XANES (average spectra) of O-adsorbed Pd , pure Pd , and PdAg alloy . The Pd -postedge structure for the Pd–Ag alloy MNPs cannot be completely collected due to the overlap with the Ag -edge XANES in the higher binding energy region. The alloyed cluster was constructed with the CRYSTALMAKER program by extending a fcc unit cell consisting of 25% Ag (two face sites) and 75% Pd (eight corner sites and four face sites) to a 55-atom cluster.
A schematic illustration of the size, surface, and alloying effects on the -electron counts (denoted as -DOS in the scheme) of Pd nanoparticles. The capping molecules of the weakly bound MNPs are not shown. For simplification purposes, the groups are used to represent the dedecanethiol capping molecules in the strongly bound MNPs.
White line parameters of Pd nanoparticles and bulk.
Data of XPS and XANES shifts of Pd MNPs relative to the bulk. (The uncertainty is for XPS, for the -edge, and for the -edge XANES).
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