Uniformly dispersed Co-Corrin/C catalysts for the study of β-O-4 bonding activity in lignin

Abstract

In this study, Co-Corrin/C catalysts with corrin active skeleton were prepared by pyrolysis under anaerobic conditions using vitamin B12 (VB12) as a precursor and activated carbon with rich mesoporous structure as a carrier. The Co-Corrin/C catalyst was applied to the oxidative cleavage reaction of lignin, showing a 92.74 % breakage of β-O-4 bonds. Density functional theory (DFT) calculations indicate that the low energy gap difference of Co-Corrin/C promotes electron transfer between Co and O. Meanwhile, the pyrrole ring in the corrin structure will be adsorbed and bonded to oxygen, which promotes the generation of large amounts of oxygen free radicals. The C_α-OH bond in the lignin aliphatic chain is oxidized to C_α=O bond under the action of oxygen radicals, which reduces the dissociation energy of the β-O-4 bond and significantly improves the oxidation efficiency. Cycling experiments proved that Co-Corrin/C has good stability.