负载型金基催化剂Au／Fe(OH)3催化苯乙烯环氧化反应

Epoxidation of Styrene via Anhydrous t-Butylhydroperoxide Catalyzed by Supported Au/Fe(OH)_3

用共沉淀法制备了Au/Fe(OH)3催化剂,以叔丁基过氧化氢为氧化剂,考察焙烧温度和金担载量等对苯乙烯环氧化反应的影响.结果表明,催化剂的焙烧温度、金担载量对苯乙烯环氧化反应有较大影响.在室温下直接合成的质量分数为4.67%的Au/Fe(OH)3催化剂对苯乙烯环氧化反应显示了很好的催化活性,于80℃反应3h苯乙烯的转化率达到84.1%,环氧苯乙烷的选择性达到71.5%.通过X射线粉末衍射(XRD)、X射线光电子能谱(XPS)和Mssbauer分析,发现催化剂的催化活性与金的价态及铁的化学存在状态有很大关系.离子态Au3+与载体Fe(OH)3的协同作用对苯乙烯环氧化反应显示出很好的催化活性.

This paper reports the epoxidation of styrene by t-butyl hydroperoxide （TBHP） over the Au/ Fe（OH）3 catalyst prepared by co-precipitation method. The influences of calcination temperature, chemical states of Au and Fe, gold loadings of the catalyst and reaction time on the activity of styrene epoxidation are studied in detail. The results suggest that the conversion and selectivity of styrene epoxide are significantly influenced by the calcination temperature and Au loadings. Au/Fe（OH） 3 with a mass fraction 4.67% shows the best activity to the epoxidation of styrene, the conversion is 84. 1% and selectivity is 71.5% under the reaction condition of 80℃ for 3 h. The XRD, XPS and Fe Mossbauer spectra indicate that Au and Fe chemical states are responsible for the good activity of Au/Fe （ OH）3 catalyst. The synergistic effect of Au^3＋ and Fe（OH）3 leads to its good activity for the styrene epoxidation.