Room-Temperature Hydrogenation of Phenol to Cyclohexanol Using Ru/C Nanosphere Catalysts

Abstract

The catalytic hydrogenation of phenol to cyclohexanol is of great industrial significance in chemical manufacturing. However, achieving efficient hydrogenation under mild conditions remains a key challenge in this field. Herein, we successfully synthesized a Ru/CNS catalyst via the NaBH₄ reduction method, which comprises highly dispersed Ru nanoparticles supported on phenolic resin-derived carbon nanospheres (CNS), and evaluated its performance in the hydrogenation of phenol to cyclohexanol. At room temperature and 1 MPa H₂, with a phenol-to-catalyst mass ratio of 3.3, the catalyst achieved complete phenol conversion within 30 min, accompanied by more than 99% selectivity to cyclohexanol. Recycling experiments confirm the excellent stability of Ru/CNS, which also exhibits high efficacy in the hydrogenation of phenol derivatives under mild conditions, converting them to the corresponding cyclohexanol products. XPS and FTIR characterizations reveal that the superior catalytic performance of Ru/CNS over Ru/C stems from the abundant C–O and nitrogen-containing functional groups on the CNS surface. These groups efficiently anchor Ru nanoparticles, significantly improving their dispersion and increasing the content of metallic Ru⁰, thereby synergistically enhancing catalytic hydrogenation activity. This study provides valuable insights into designing efficient catalysts for cyclohexanol production under mild conditions.