Amorphous Ni-Ru bimetallic phosphide composites as efficient catalysts for the hydrogenolysis of diphenyl ether and lignin

Gas-phase SiO2-supported amorphous Ni-Ru bimetallic phosphide composite catalysts (NiRuP/SiO2) are prepared in this study. Using diphenyl ether as a lignin-related model compound, the reactivity of NiRuP/SiO2 in the catalytic hydrogenolysis of a 4-O-5-type linkage is investigated under mild conditions. The molar ratios of nNi/ nRu and nP/nM have a significant influence on the acidic properties of the bimetallic phosphides. The total acidity exhibits a strong linear correlation with the hydrogenolysis yield of diphenyl ether. Among all the catalysts, the Ni5RuP2/SiO2 catalyst shows high catalytic activities for the hydrogenolysis of diphenyl ether without excessive hydrogenation and is introduced to depolymerize lignin. Furthermore, 2D-HSQC-NMR spectroscopy analysis revealed that Ni5RuP2/SiO2 exhibited high activity for C-O cleavage. The predominant hydrogenolysis products from lignin are higher value-added chemicals. The findings of this work are beneficial to the biorefinery industry and provide an alternative method to make better use of lignin.

Automated summary

Gas-phase SiO2-supported amorphous Ni-Ru bimetallic phosphide composite catalysts (NiRuP/SiO2) were prepared and investigated for the catalytic hydrogenolysis of a lignin-related model compound. The Ni5RuP2/SiO2 catalyst showed high catalytic activity for the hydrogenolysis reaction without excessive hydrogenation, providing an alternative method for lignin depolymerization.