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 Pt on Au nanoparticles of two size ranges (Au-I: 10 ± 1.2 nm, Au-II: 3 ± 0.6 nm) up to different atomic Pt : Au ratios (m) was used to prepare two series of samples named Ptm⁁Au-I and Ptm⁁Au-II particles, respectively. The obtained Ptm⁁Au particles were characterized with TEM, XPS, UV-Vis and XRD techniques, and then loaded on conventional Vulcan XC-72 carbon to make Ptm⁁Au/C electrocatalysts. Cyclic voltammetry (CV) measurements showed that the electrochemical active surface area (EAS) and Pt utilization (UPt) in Ptm⁁Au/C were enhanced remarkably at m
≤ 0.2 for Ptm⁁Au-I/C or m
≤ 0.5 for Ptm⁁Au-II/C, in comparison to conventional Pt/C electrocatalyst. In particular, UPt was enhanced to nearly 100% in Ptm⁁Au-I/C catalysts at m
≤ 0.05 and in Ptm⁁Au-II/C at m
≤ 0.1. In the CV measurement of methanol electro-oxidation, the specific mass activity of Pt in Ptm⁁Au/C catalysts was found in proportional to UPt, confirming that the enhancement of Pt utilization is essential for the development of highly active Pt-based electrocatalysts. The highly dispersed Pt entities on Au nanoparticles proved to be stable during the electro-oxidation of methanol. Our study also showed that the use of smaller Au nanoparticles is advantageous for the generation of more active Pt catalyst at higher atomic Pt : Au ratios.