This paper reports on the synthesis and use of an Ag/zeolite nanocomposite as a separable catalyst for the ligand-free hydroxylation of phenylboronic acid to phenol and the reduction of 4-nitrophenol (4-NP), methyl orange (MO), congo red (CR), methylene blue (MB) and rhodamine B (RhB) at room temperature. The Ag/zeolite nanocomposite was prepared using the extract of a leaf of Euphorbia prolifera and characterized by FT-IR, XRD, FE-SEM, EDS and TEM analyses. The catalyst was quantitatively recovered and reused without significant loss in the catalytic activity. [ABSTRACT FROM AUTHOR]