Molybdenum disulfide promoted co-catalyzed alkoxycarbonylation

• Published in: Journal of catalysis 2024-02, Vol.430, p.115349, Article 115349
• Main Authors: Zheng, Zhaohui, Zhou, Hao, Deng, Li, Jia, Xiaofei, Li, Yuehui
• Format: Article
• Language: English
• Subjects: Alkoxycarbonylation; Cobalt salt; External reductant; Molybdenum disulfide; Redox potential
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2024.115349

A novel approach involving molybdenum disulfide (MoS2) promoted in-situ generation of cobalt catalyst for alkoxycarbonylation reaction was presented. Cobalt(II) salts were transformed to highly active cobalt carbonyl species without using external reducing agents or applying harsh reaction conditions. Mechanism studies revealed that the defect-rich MoS2 played the key role to abstract electron from CO and to reduce Co2+. [Display omitted] •S-defect MoS2 promoted cobalt(II) reduction to cobalt(0) with CO as reductant under mild conditions.•Inexpensive and stable cobalt acetate as catalyst precursor instead of Co2(CO)8.•MoS2 with sulfur defects serves dual roles to abstract electron from CO and to reduce Co2+.•This work provides strategies for in-situ generation of low-valence metallic species. 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.