Highly efficient conversion of phenol to cyclohexanone on Pd-based catalysts by cobalt doping

Efficient catalysts are still the key to practical industrial applications. In this work, Pd-based catalyst was modified by doping metal Co to obtain Pd-Co@mSiO2 bimetallic core–shell catalyst. The modified bimetallic core–shell catalyst was used in the hydrogenation of phenol, and the catalytic results showed that the Co modification effectively improved the catalytic performance of the Pd-based catalyst, especially, it reduced the activation energy of the reaction and greatly improve the conversion of phenol. Combined with characterization, it was found that Co doping reduced the particle size of Pd metal particles and affected the adsorption capacity of substrate phenol on the surface of Pd metal. The conversion of phenol was close to 99.9 % within 1 h at 80 °C, while the selectivity of cyclohexanone reached 95.4 %. In addition, the core–shell structure provided a stable environment for the catalyst, which still maintained high activity after being recycled for 5 times.