Aerobic epoxidation of olefins over the composite catalysts of Co-ZSM-5(L) with bi-/tridentate Schiff-base ligands

作者：Qi, B.; Lu, X. -H.; Fang, S. -Y.; Lei, J.; Dong, Y. -L.; Zhou, D.; Xia, Q. -H.^*

来源：Journal of Molecular Catalysis A: Chemical , 2011, 334(1-2): 44-51.

DOI：10.1016/j.molcata.2010.10.021

• Epoxidation
• Alkene
• Co-L
• Co-ZSM-5(L)
• Schiff-base ligands
• Air

Three tridentate or bidentate Schiff-base ligands inclusive of salicylaldehyde benzoylhydrazone (L-1), vanillic aldehyde benzoylhydrazone (L-2) and 4-methyl benzaldehyde benzoylhydrazone (L-3), have been designed, synthesized and employed to coordinate with Co2+ ions and ion-exchanged Co-ZSM-5 forming several Co-L complexes and Co-ZSM-5(L) composite catalysts. The catalytic epoxidation of several alkenes with dry air has been carried out at 90 degrees C under atmospheric pressure using Co-L complexes and Co-ZSM-5(L) catalysts (using TBHP in small amounts as the initiator). In contrast, the catalysts Co-ZSM-5(L) shows higher catalytic activity than Co-ZSM-5 itself and Co-L complexes. Among three Co-ZSM-5(L) catalysts, Co-ZSM-5(L-1) exhibits the highest activity for the selective epoxidation of alkenes. Recycling studies show the recyclability of Co-ZSM-5(L-1) as a heterogeneous catalyst, which does not lose the catalytic activity after even eight reuses appreciably. Based on the experiments, one possible reaction mechanism is proposed.

• 出版日期2011-1-4
• 单位湖北大学