We introduce a novel single-step method capable of a continuous production of Pt catalysts supported on carbon agglomerates for the preparation of the fuel electrode. An acetylene-air diffusion flame is employed as heat and carbon sources, and Pt(acac)(2)-containing xylene droplets are injected into the flame. A sampling height from the burner top, initial concentration of Pt(acac)(2), and acetylene flow rate are demonstrated as efficient systematic parameters to control the size (from 2 to 7 nm) and surface coverage (or content up to 60 wt %) of spherical Pt particles. A variety of characterization methods manifest that the Pt exists mostly in a metallic form and carbon agglomerates are in good crystalline order. Finally, the electrochemical activity is confirmed to be higher than 74.9 m(2) g(-1) Pt, more efficient than an equivalent commercial (E-TEK 10 wt % Pt) catalyst.