Single-atom copper catalyst for the S-arylation reaction to produce diaryl disulfides

Abstract

Single-atom Cu supported on CeO_x nanorod catalysts (Cu₁/CeO_x) have been synthesized through the anchoring of copper by terminal hydroxyl groups on the CeO_x surface. The oxygen defect characteristics of the CeO_x nanorods promote electron transfer between Cu and CeO_x through a Ce–O–Cu interface, which realizes flexible electronic regulation of the Cu sites. Single-atom Cu species with an oxidation state of between +1 and +2 were formed, which was confirmed by X-ray photoelectron spectroscopy, X-ray fine structure spectroscopy, and electron paramagnetic resonance spectroscopy. Cu₁/CeO_x emerged as a catalyst with advanced catalytic performance for elemental sulfur in S-arylation using aryl iodides, achieving 97.1% iodobenzene conversion and 94.8% selectivity toward diphenyl disulfide. The substituted iodobenzene with different electronic or steric groups successfully realized S-arylation and produced the corresponding diaryl disulfides with high selectivity. The fully exposed single-atom Cu with flexible electronic characteristics successively realized oxidative addition or coordination of multiple substrates, making it possible to obtain diaryl disulfide with high selectivity.