Constructing materials with high-density interfaces offers a very promising route to enable high-performance nanocatalysts. Herein, a one-pot method to synthetize CuOx-CeO2 spherical catalysts with high-density interfaces is developed by controlling the growth condition so that the CuOx can only nucleate and grow via heterogeneous mode. The synthesis method ensures fine dispersion of CuOx over CeO2 and the density of interface between CuOx and CeO2. The generation of the species of Cu+, Ce3+, and oxygen vacancies are enhanced by the interface interaction. And the reduction of copper ions to metals is effectively suppressed, which helps to avoid deactivation of catalyst at high temperature. When catalyzing the CO preferential oxidation reaction (CO-PROX), the CuOx-CeO2 composite with high-density interfaces exhibits a strikingly high catalytic oxidation activity at a broad operating temperature window (i.e. CO 100% conversion, 95-235 degrees C). The heterogeneous nucleation methodology of synthesizing composite with high-density interfaces reported in this work also applies to other materials system. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.