Highly efficient hydrogenation of phenol and lignin-derived compounds over Ru-Rh bimetallic nanoparticles supported on α-Al2O3 at room temperature

Abstract

Catalytic hydrogenation of phenol and lignin-derived compounds is an important strategy to produce chemical and pharmaceutical intermediates, but it is still a challenge to achieve this process under mild conditions. Herein, the bimetallic Ru-Rh/α-Al2O3 catalyst was successfully prepared and used for the direct hydrogenation of phenol and lignin-derived compounds. The results of this study illustrate that Ru-Rh/α-Al2O3 exhibits the highest activity for the hydrogenation of phenol and diphenyl ether among these catalysts. Phenol can be completely converted to the target product of cyclohexanol over Ru-Rh/α-Al2O3 under extremely mild conditions (30 °C, 1 MPa H2, 90 min). With Ru-Rh/α-Al2O3 as the catalyst, a variety of other unsaturated substrates are also efficiently hydrogenated to the corresponding ring-saturated products with a high yield. The characterizations reveal that the strong interaction formed between Ru and Rh is mainly responsible for the enhancement of the hydrogenation activity. The construction of the bimetallic Ru-Rh/α-Al2O3 catalyst can accelerate the high value-added utilization of phenol and lignin-derived compounds.