This work attempts to enhance platinum utilization in a Pt-based electrocatalyst by the tuned covering of gold nanoparticles with small Pt entities. Reductive deposition of platinum (donated as Pt) on gold (donated as Au) nanoparticles with different atomic Pt:Au ratios was used to prepare a series of samples named Au-core@Pt(cluster)particles. UV-vis spectrum, TEM and XRD were used to characterize the core-cluster samples. The electrochemical tests (cyclic voltammerty (CV)) showed that the core-cluster structure could significantly improve the catalytic activity of Au-Pt towards electrooxidation of formic acid, in comparison to commercial Pt/C electrocatalyst. The improvement of activity is ascribed to the interaction between Au core and Pt cluster. (C) 2017 Elsevier B.V. All rights reserved.