“…These improvements have been made in order to increase the accessible sites/zones on the surface of catalyst, greater catalyst reactivity and selectivity, thermal stability and nally easy separation. Fe 3 O 4 , 12,13 NiFe 2 O 4 , [14][15][16] CoFe 2 O 4 , 17 CuFe 2 O 4 , [18][19][20] MnFe 2 O 4 , 21 Ni-Cu-ZnFe 2 O 4 , 22 BiFeO 3 , 23 FeAl 2 O 4 24 and ZnCrFeO 4 25 as a core, and metals, [26][27][28] silica, [29][30][31][32] polymers, [33][34][35] carbon nanotubes and sheets, [36][37][38][39][40] cellulose, 41 small organic molecules, 42,43 ionic liquids, 44,45 and organosulfonic acids 46,47 have been used as a coating.…”