Fig. 5: Operando XPS and NEXAFS on LCC Pd. | Nature Communications

Fig. 5: Operando XPS and NEXAFS on LCC Pd.

From: Rationally designed laterally-condensed-catalysts deliver robust activity and selectivity for ethylene production in acetylene hydrogenation

Fig. 5

a Pd 3d5/2 spectra and (b) Pd L3-edge of a LCC Pd (3 nm) deposited on SiO2(20 nm)/Si(100) before the reaction (UHV, RT) and during the operando acetylene hydrogenation at 100 °C. Kinetic energy of photoelectrons is 400 eV. The majority phase (blue) is assigned to Pd:C whereas the minority phase (red) is metallic Pd. The different line profiles in XPS arise from the loss of core hole coupling with the valence electron density near the Fermi edge as a consequence of the Pd:C formation (see Fig. 4a). The broad line for Pd:C in the NEXAFS indicates the inhomogeneity of the distribution of carbon giving rise to locally different electronic structures (see also theory in Fig. 3a and Supplementary Fig. 1). Note that the depth of information is strongly different for XPS and NEXAFS; XPS at 400 eV kinetic energy probes surface-sensitive, whereas the NEXAFS measures through the whole Pd nanostructures. Source Data.

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