Herein, we synthesized CeO2 nanocrystals (Ce250) with a large number of surface lattice defects by calcining the superfine Ce(OH)(3) nanowires at 250 degrees C. They were then utilized as the support of the CuO catalysts for CO preferential oxidation (CO PROX). The strong interaction between CuO and CeO2 is the key factor to improve the catalytic activity, and our results show that the surface lattice defects on the CeO2 support can strengthen the interaction between CuO and CeO2 during the catalyst preparation procedure. With the increase of the calcination temperature, the surface areas of the CuO/CeO2 catalysts gradually drops, but the interaction between CuO and CeO2 is strengthened. Their catalytic activities present a "volcano" type, and the CuCe500 calcined at 500 degrees C shows the highest catalytic activity. (C) 2017 Elsevier B.V. All rights reserved.