Vol.:(0123456789) 1 3 Catalysis Letters https://doi.org/10.1007/s10562-020-03292-y Inducing the Catalytic Activity in SrFe 12 O 19 Via Chemical Modifcation P. N. Anantharamaiah 1  · Sanjukta Mondal 1  · Sujoy Saha 2 Received: 24 December 2019 / Accepted: 14 June 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract In this study, we demonstrate that the catalytic activity could be induced in the hard magnetic strontium hexaferrite (SrFe 12 O 19 ) system by replacing a small fraction of Fe by Cu. Nanocrystalline SrFe 12 O 19 and SrCu 0.3 Fe 11.7 O 19 samples were synthesized by a tartrate-gel method and their structural, microstructural, specifc surface area and magnetic properties were studies. Subsequently, the nanocrystalline hexaferrite powders were employed as catalysts to drive 4-nitrophenol reduction reaction using the NaBH 4 as the reducing agent. The progress of the catalytic reactions was evaluated using UV–visible spectrophotometer. The unsubstituted sample was found to be catalytically inactive whereas SrCu 0.3 Fe 11.7 O 19 sample showed superior catalytic performance in transforming 4-nitrophenol to 4-aminophenol within 8 min. Reusability test confrmed that the SrCu 0.3 Fe 11.7 O 19 catalyst retains its 100% activity even after fve consecutive cycles. In addition, the efect of crystallite size of SrCu 0.3 Fe 11.7 O 19 on the catalytic reduction reaction of 4-nitrophenol was investigated. The results indicated that the time taken to complete the reduction reaction has been increased as size of the crystallites increased, probably due to decrease in the large number of surface active sites of the catalyst. * P. N. Anantharamaiah anantharamaiah.cy.mp@msruas.ac.in 1 Department of Chemistry, Faculty of Mathematical and Physical Sciences, M. S. Ramaiah University of Applied Sciences, Bangalore 560058, India 2 Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India