The promoting effect of sulfur sources is an intriguing but poorly understood phenomenon. Herein, we studied the treatment of PdCu bimetallic nanoparticles (NPs) with different amounts of sulfur powder. Low-level sulfidation led to the generation of a Pd30Cu10S9 NP catalyst consisting of surface enriched Pd NPs, electron deficient Pd and Cu, as well as zero valence sulfur. The Pd30Cu10S9 NP catalyst showed pronouncedly enhanced activity and selectivity in the semihydrogenation of alkynes. Our study revealed for the first time a possible cause for the promoting effect of sulfur at the atomic level, suggesting a new strategy in catalyst design.

The aerobic oxidation of diaryl and aryl(hetero) methylenes into ketones, catalyzed by Ag/C nanoparticles under mild conditions, was successfully developed. This method features a wide scope of substrates, good yields, and uncomplicated recycling of the catalyst.

A highly efficient and selective bimetallic Pd_0.88Co_0.12 nanoparticle catalyst was developed for the direct N-formylation of amines by carbon monoxide. This catalyst is compatible with a wide range of substrates, affording various synthetically useful formamides under practical and mild reaction conditions.