Researchers developed a cobalt-zinc dual single-atom catalyst that converts C-lignin into catechol chemicals with an 84.6% yield, according to a peer-reviewed study published in Nature Communications. The low-loaded catalyst, designated CoSA–ZnSA@NC, achieved 82% selectivity toward 4-propylcatechol and delivered a turnover number five times higher than precious ruthenium-on-carbon.
C-lignin is a natural biopolymer made of caffeyl alcohol subunits linked by benzodioxane motifs, making it a target feedstock for direct catechol production. Hydrogenolysis of the material is typically hindered by steric congestion and the high bond dissociation energies required to break vicinal carbon-oxygen bonds within benzodioxane structures.
Mechanistic investigations revealed that the catalyst relies on synergistic dual atomic sites to carry out a quasi-concerted cleavage of those vicinal C–O bonds. In the system, zinc species act as directing centers while cobalt species serve as active centers. The major resulting product, 4-propylcatechol, can be purified and upgraded into diverse value-added chemical molecules.
The research was conducted by teams at the State Key Laboratory of Efficient Production of Forest Resources and the Beijing Key Laboratory of Lignocellulosic Chemistry at Beijing Forestry University, alongside the National Engineering Research Center of New Energy Power Generation at North China Electric Power University. The work received analytical support from the BioNMR facility at Tsinghua University and funding from the National Natural Science Foundation of China, the Beijing Natural Science Foundation, and the Fundamental Research Funds for the Central Universities.
