Au-Pd alloy cooperates with covalent triazine frameworks for the catalytic oxidative cleavage of β-O-4 linkage
To design high efficient catalyst for the cleavage of C-O/C-C bond is the key task for the depolymerization of lignin. Bimetallic alloy catalysts Au-Pd-CTFs were developed to be effective in the oxidative cleavage of β-O-4 lignin model compounds with O2. Au-Pd nanoparticles with an Au/Pd molar ratio between 1:1 and 1:1.5 showed the highest cleavage efficiency. The kinetics of the reaction process revealed that a synergistic effect between Au and Pd played an crucial role in the oxidation of Cα-OH into Cα=O, which was the rate-determing step for the whole oxidative cleavage process. Further insight revealed the cooperation effect between Au-Pd nanoparticles and the support covalent triazine frameworks (CTFs) facilitated the cleavage of the formed β-O-4 ketone compound to the corresponding aromatics. In addition, Au-Pd-CTFs catalysts also showed efficiency in the oxidative transformation of the organosolv lignin. This catalytic system will provide guidance in the oxidative cleavage of β-O-4 linkages in lignin.