Liquid-Phase Selective Hydrogenation of Phenol to Cyclohexanone over Pd-Ce-B/Hydrotalcite Catalyst

Supported Pd-Ce-B catalysts were prepared by chemical reduction of Pd and Ce ions that were deposited on hydrotalcite (HT) with an Al3+/(Al3++Mg2+) molar ratio of 0.2. In the reaction of liquid-phase selective hydrogenation of phenol, the as-prepared Pd-Ce-B/HT catalyst exhibited much higher activity and selectivity for cyclohexanone than Pd-Ce-B/Al2O3, Pd-Ce-B/MgO, and Pd-Ce-B/SiO2. The maximum phenol conversion and selectivity for cyclohexanone over 5.8%Pd-Ce-B/HT reached 82.0% and 80.3%, respectively. Based on the results of various characterizations, the catalyst structure-activity correlation and the promoting effects of the Ce dopant and acidic-basic properties of the support on the catalyst behavior were discussed.