We report the facile synthesis of environmentally benign Cu NPs/perlite composites without employing any toxic reductants or capping agents. Renewable natural Euphorbia esula L. not only functioned as a reductant, but also served as a stabilizer for the formation of Cu NPs. Cu NPs synthesized using aqueous extract of the leaves of Euphorbia esula L. was immobilized on perlite by a very simple and inexpensive method. The structural investigation was performed using XRF, XRD, SEM, EDS, TEM, TG-DTA, BET and FT-IR. The Cu NPs/perlite shows favorable activity and separability on the catalytic reduction of 4-nitrophenol, and can be reused several times without a decrease in the catalytic activity. Their reaction rate constant was calculated according to the pseudo-first-order reaction equation. (C) 2015 Elsevier B.V. All rights reserved.