The epoxidation of alkenes to the corresponding epoxides plays a vital role in fine chemical engineering. Magnetic nanocomposite catalyst RGO/Fe₃O₄@C_-N-Co₃O₄ (RGO: reduced graphene oxide) involving Co₃O₄ nanoparticles immobilized on magnetic N-doped graphene was prepared by a hydrothermal method. N-dopants in the RGO/Fe₃O₄@C_-N-Co₃O₄ can strengthen the interaction between Co₃O₄ nanoparticles and the support. RGO/Fe₃O₄@C_-N-Co₃O₄ revealed higher catalytic reactivity (i.e. 93.2% conversion of styrene and 88.4% selectivity to styrene oxide) as compared to bulk Co₃O₄, and Co₃O₄ supported on N-free RGO/Fe₃O₄@C due to site-isolation, good dispersion of Co₃O₄ nanoparticles and efficiently synergistic effect between Co₃O₄ and the magnetic support. In addition, the catalyst displayed good recoverability by simple magnetic separation with negligible loss in activity and selectivity within several successive runs due to superparamagnetism.

烯烃环氧化为相应的环氧化物在精细化学工程中起着至关重要的作用。通过水热法制备了固定在磁性N掺杂石墨烯上的Co ₃ O ₄纳米颗粒的磁性纳米复合催化剂RGO / Fe ₃ O ₄ @C _-N -Co ₃ O ₄（RGO：还原石墨烯）。RGO / Fe ₃ O ₄ @C _-N -Co ₃ O ₄中的N掺杂剂可增强Co ₃ O ₄纳米颗粒与载体之间的相互作用。RGO /铁₃ O ₄ @C_-N -Co ₃ O ₄与散装在无氮RGO / Fe ₃ O上的Co ₃ O ₄和Co ₃ O ₄相比，具有更高的催化反应活性（即，苯乙烯转化率为93.2％，选择性转化为氧化苯乙烯的选择性为88.4％）₄ @C由于现场隔离，钴的分散性好₃ ö _4个纳米颗粒和Co之间有效地协同作用₃ Ò ₄和磁性支持。另外，由于超顺磁性，该催化剂通过简单的磁分离表现出良好的可回收性，在连续的几次运行中，活性和选择性的损失可忽略不计。