Coordination adsorption of Ag(I) on cobalt-ferrous oxalates and their derived Ag/CoFe2O4 for catalytic hydrogenation reactions

Well-defined deposition of noble metal nanoparticles is attractive for the synthesis of heterogeneous metal catalysts with excellent activity, stability, and easy separability. Herein, a facile method combining surface coordination deposition with thermal decomposition has been proposed to fabricate Ag/CoFe 2 O 4 composites as magnetic catalysts for hydrogenation reduction of 4-nitrophenol and 2-nitroaniline. This method involved the adsorption of silver ions on cobalt-ferrous oxalate through the surface coordination, and then the thermal decomposition into Ag/CoFe 2 O 4 . The characterizations of XRD , SEM, FTIR, BET, VSM , XPS and Element mapping were utilized to reveal that Ag/CoFe 2 O 4 exhibited a magnetic saturation of 40.4 emu g −1 , a specific surface area of 58.8 m 2  g -1 , and an even distribution of metallic Ag on CoFe 2 O 4 particles. Catalytic reduction tests of 4-nitrophenol and 2-nitroaniline indicated that the Ag contents in Ag/CoFe 2 O 4 seriously affected the catalytic activity of the catalysts. Moreover, the durability test showed that Ag/CoFe 2 O 4 still preserved ∼74.6% of the initial catalytic activity even at the 20th run.