Operando X‐ray Spectroscopy Study of Pd and Pd–Au Laterally Condensed Catalysts during Selective Acetylene Hydrogenation: The Role of Carbon

In this study, near ambient pressure X-ray photoelectron and X-ray absorption spectroscopy (NAP-XPS and NAP-XAS) were performed during the selective acetylene hydrogenation reaction on Pd and Pd-Au laterally condensed catalysts. The activity and selectivity of this reaction are strongly influenced by the incorporation of carbon into the Pd and Pd-Au lattice, which is investigated by both experiment and theory. We find that Pd can take up much more carbon than Pd-Au, which can be used to tune the activity of the catalyst during the hydrogenation reactions. The amount of the carbonaceous species dissolved in the Pd and Pd-Au lattice was quantified and their effect on the chemical and the electronic structure was tracked by means of operando spectroscopy throughout different stages of the acetylene hydrogenation reaction.