Molybdenum disulfide promoted co-catalyzed alkoxycarbonylation

Herein, we presented a novel approach involving molybdenum disulfide (MoS2) promoted in-situ generation of active cobalt catalyst for alkoxycarbonylation reaction, an industrial process for ester production. In this scenario, inexpensive cobalt(II) salts were transformed to highly active cobalt carbonyl species without using external reducing reagents or applying harsh reaction conditions. In-situ formed cobalt catalyst enabled high activity comparable to that using Co2(CO)8 as catalyst. The generation of [Co(CO)4]- anion under mild conditions was confirmed by both in-situ Fourier transformed infrared spectroscopy (FT-IR) and electrospray ionization mass spectrometry (ESI-MS). The detailed mechanism of this transformation revealed by X-ray photoelectron spectroscopy (XPS) and electrochemical analysis involved that carbon monoxide (CO) served dual roles as reductant and carbonyl ligand while the electron transfer to Co2+ cation took place over the MoS2 surface with sulfur defects.