From cyclohexanol to aniline: A novel dehydrogenation-amination-dehydrogenation strategy based on Pt-based catalyst

Anilines are essential building blocks and widely used in the synthesis of pharmaceuticals, agrochemicals, polymers and hetercycles, but its production is highly relied on traditional methods with petroleum-based chemicals as basis. Herein, a novel dehydrogenation-amination-dehydrogenation strategy is developed for the first time to the synthesis of aniline from cyclohexanol over various Pt-based catalysts. It is shown that Pt/CeO2 catalyst has the best performance. Comprehensive studies find that in the three catalytic steps, i. e., the dehy- drogenation of cyclohexanol, the amination of cyclohexanone and the dehydrogenation of cyclohexylamine, the dehydrogenation of cyclohexylamine to aniline is the rate-determining step. Structure-performance relationship studies show that compared with Pt/C and Pt/Al2O3 catalysts, the excellent performance of Pt/CeO2 is originated from its suitable basic property and smaller Pt particle size, which are more favorable for the dehydrogenation steps. Meanwhile, 100 h long-term stability is achieved and this strategy is also extended to other alcohol. This is a new strategy for the construction of aniline from simple alcohol and will provide a new and promising direction for the synthesis of aromatic amine with the features of cheapness, green and sustainability.