In this research nanocatalysts containing 5, 10 and 15 wt.% of Ni, dispersed by sonication over CeO2-clinoptilolite composite support were compared toward total oxidation of toluene. Their catalytic performance at different temperatures between 150 and 350 degrees C was studied based on the oxidative destruction of toluene. The results indicated that the activity of Ni/CeO2-clinoptilolite nanocatalyst for toluene oxidation increased from 33 to 44% at 250 degrees C by employing sonochemical method in synthesis of catalyst. Meanwhile, the catalytic activity was also improved when Ni content was increased from 5 to 10 and 15 wt.%. With the aid of several characterization techniques like XRD, FESEM, PSD, EDX, BET and FTIR, the correlation between nanocatalyst structure and its activity was addressed. It is indicated that sonochemical method can lift the catalytic activity due to the better dispersion of catalyst active components and also higher surface area. Among sonicated samples, 15 wt.% Ni nanocatalyst showed the highest toluene oxidation due to the better dispersion of catalyst active components and hence to more effective catalytic sites. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.