Its due to acidity of the surface layer groups and due to layer structure that can be easy incorporated with exchanging ions or molecules.

Can you be more specific? The high activity for what? In acid catalysed reactions the acidic phosphate groups in these layered compounds are the active materials. However, you need to be careful with the interpretation of the data since zirconium phosphate may leach phosphate groups into solution (see B. Brack et al. Microporous and Mesoporous Materials 41 (2000) 149)