A platinum nanowire network (approximate circle divide 4 nm) with silica nanoparticle (Pt-net/SiO2) spacers was prepared via spray drying and hydrogen reduction. The large network had few grain boundaries of crystalline platinum and enclosed SiO2 nanoparticles (average circle divide 75 nm). These properties contributed to thermal and chemical stability of the structure. The nanowire network had a high electrochemical surface area (31.3 m(2) g-(-1)(Pt)), and acted as a catalyst for the oxygen reduction reaction. Its initial mass activity (110.5A g-(-1)(Pt) at 0.85 V-RHE) was high compared to commercial Pt/C catalyst. Because of the chemical stability of the silica and the minimal amount of low-coordinated platinum in the platinum nanowires, Pt-net/SiO2 retained 77% of its initial activity after 27 000 redox cycles compared to 57% for commercial Pt/C. We also demonstrate that the hydrogen peroxide generation from Pt-net/SiO2 was less than half that from Pt/C. (C) 2012 Elsevier B.V. All rights reserved.