Please read some of the recent reviw articles listed below; tehe saliet features are their retrieval via an external magnet after completion of the reactions besides a large surface area which dictates their enhanced catalytic capability:
1. Nano-Magnetite (Fe3O4) as Support for Recyclable Nano-Catalysts in the Development of Sustainable Methodologies.
M. B. Gawande, P. S. Branco and R. S. Varma: Chem. Soc. Rev., 42, 3371-3393 (2013).
2. Magnetically Retrievable Catalysts for Organic Synthesis.
R. B. Nasir Baig and R. S. Varma: Chem. Commun., 49, 752-770 (2013).
3. Organic Synthesis via Magnetic Attraction: Benign and Sustainable Protocols Using Magnetic Nanoferrites.
R. B. Nasir Baig and R. S. Varma: Green Chem., 15, 398-417 (2013).
The last reference gives experimental details for various C-C , C-N bond forming reactions