摘要
以正硅酸乙酯为硅源,Pluronic三嵌段共聚物P123或四丙基氢氧化铵(TPAOH)为结构调节剂,采用一锅温和水热法成功地合成了Fe-修饰的SiO_2;并以其为载体,采用等体积浸渍法制备了负载型0.3%Pd-3%Fe/SiO_2催化剂。采用XRD、N2吸附-脱附、CO脉冲吸附法、微型浆态床反应器和高效液相色谱对产物的物相结构、织构性质和2-乙基蒽醌加氢性能进行了表征和测试。结果表明,该催化剂具有较规整的孔道、较窄的孔径分布和适中的比表面积;在蒽醌加氢反应中,该催化剂的氢化效率可达13.1g/L、选择性可达66.1%,并且反应4h时的氢化效率仍高达11g/L。相比之下,典型的工业Pd-催化剂反应1.5h后便因副反应过多而无法进行,且氢化效率仅有5.4g/L,选择性仅有26.2%。研究还发现,以P123为结构调节剂时,掺杂Fe可以提高催化剂的选择性;而以TPAOH为结构调节剂时,掺杂Fe可以同时显著地改善催化剂的活性和选择性。
Fe-modified SiO_2 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/SiO_2 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 excessiveside 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.
出处
《化工进展》
EI
CAS
CSCD
北大核心
2016年第12期3913-3918,共6页
Chemical Industry and Engineering Progress
