One-pot hydrothermal-impregnation synthesis of Pd-Fe/SiO2 catalyst with enhanced catalytic performance towards 2-ethylanthraquinone hydrogenation

Fe-modified SiO2 were successfully synthesized via a moderate one-pot hydrothermal process using tetraethoxysilane(TEOS) as silicon source, and Pluronic triblock copolymer P123 or tetrapropyl ammonium hydroxide(TPAOH) as structure directing agent. Then supported catalysts of 0.3%Pd-3%Fe/SiO2 were prepared by incipient impregnation method. The phase structures, texture properties were characterized by XRD, N2 adsorption-desorption, CO pulse adsorption and the catalytic performance towards hydrogenation of 2-ethylanthraquinone was evaluated in a micro slurry bed reactor. The results showed that the prepared catalysts possess preferably mesoporous structure, structured channel, narrow pore size distribution and medium specific surface area. In the 2-ethylanthraquinone hydrogenation reaction, the prepared catalysts exhibited a high hydrogenation efficiency of 13.1g/L and a high selectivity of 66.1%, and all the catalysts still had an hydrogenation efficiency of 11g/L after 4h. In contrast, industrial catalyst was unable to work after 1.5h due to excessive side reactions, and its hydrogenation efficiency and selectivity were only 5.4g/L and 26.2%, respectively. The study also showed that when P123 was used as the structure directing agent, the doped Fe- could increase the selectivity of the catalyst, and when TPAOH was used as structure directing agent, the doped Fe- can significantly improve both the activity and selectivity of the catalyst. © 2016, Chemical Industry Press. All right reserved.