Boosting Higher Selectivity for Thymol Hydrogenation Reaction over Ni/Ce Catalyst

The production of menthol via thymol hydrogenation is an industrial technology but is challenging due to the unsatisfied selectivity to menthol. Herein, Ni/Ce catalysts were prepared and used in thymol hydrogenation. A high selectivity of menthol was achieved over Ni-4/Ce-1 catalysts under the optimized reaction condition. Ce incorporation can improve both the activity of Ni catalyst and the selectivity to menthol. To reveal the functions of Ce, catalyst characterizations were conducted. The catalytic activity improvement may be related to the remarkable increase in the surface area of the catalyst and the lower crystalline sizes of Ni that take place when a tiny amount of Ce is incorporated into Ni. Higher selectivity to menthol may be related to the modification of the acidity of an Ni catalyst. In addition, the stability of the Ni-4/Ce-1 catalysts was also evaluated, and after five recycles, the Ni-4/Ce-1 catalysts exhibited outstanding catalytic activity and stability.