Construction of a P/S dual-atom coordinated Co heterogeneous mononuclear complex catalyst for hydroformylation

To replace scarce Rh resources and enhance the recyclability of the metal, we report a novel heterogeneous cobalt mononuclear complex catalyst, which possesses phosphorus-rich polymer backbone and P/S dual-atom coordination sites. This catalyst exhibited a much higher hydroformylation performance of 2,5-DHF compared to the Co-P homogeneous analogue, increasing conversion by 70% and shifting selectivity toward high-value-added 3-Formyl-THF by 15%. Under the optimal reaction conditions, the heterogeneous mononuclear complex Co 1 /POPs-PPh 3 -5P&2S catalyst displayed comparable performance of precious Rh-based catalysts, achieving a 96.8% conversion of 2,5-DHF and an 85.6% selectivity of 3-Formyl-THF for at least 5 runs. Comprehensive characterizations (extended X-ray absorption fine structure, X-ray photoelectron spectroscopy, in-situ Fourier transformed infrared, etc .) demonstrated that P/S dual-site coordination regulated the electronic structure of Co active centers. Notably, the incorporation of sulfur increased the difference in adsorption energy barriers between the substrate and its isomerized substrate, thereby promoting the massive generation of 3-Formyl-THF. Besides, time-of-flight secondary ion mass spectrometry and density functional theory calculations successfully evidenced the complete structure of the active center and established a coherent reaction mechanism. This study successfully developed a heterogeneous catalyst system based on a mononuclear cobalt complex, achieving a new strategy for non-noble metal catalysis and providing new insights into energy conservation and efficient resource utilization.