Understanding Palladium Hydrogenation Catalysts: When the Nature of the Reactive Molecule Controls the Nature of the Catalyst Active Phase

Alkynes of everything: Fundamental differences in the palladium‐catalyzed hydrogenation of double and triple CC bonds arise from marked differences in the composition of the catalyst surface. In situ X‐ray photoelectron spectroscopy of the near‐surface region of active palladium catalysts uncovers strong links between the chemical nature of the (alkyne/alkene) reactive molecules and the subsurface state of the catalyst (I–IV).