• acetylene;
  • carbide;
  • hydrogenation;
  • nanocrystals;
  • palladium;
  • structure sensitivity;
  • support effects
Thumbnail image of graphical abstract

Combined effects for improved catalysis! The cover picture shows the evolution of the active phase of shape-controlled palladium nanocrystals (NCs) during acetylene hydrogenation, depending on the nature of the support. In their Communication on p. 767 ff., M. Crespo-Quesada, S. Yoon et al. show that the structure sensitivity of a chemical reaction is a complex phenomenon that originates from the reconstruction of the Pd-NCs in response to the reactive environment. This reconstruction is sensitive to the support used. Indeed, acetylene hydrogenation is a structure-sensitive reaction [Pd(111) in octahedra is more active than Pd(100) in cubes]. However, the catalytically active and selective palladium carbide (PdCx) phase was readily formed in Pd-NCs on the SiO2 (much faster on Pd cubes than on Pd octahedra), whereas a markedly less active PdZn phase was formed on the ZnO-supported Pd NCs.