Design of catalysts with advanced structures has been extensively studied. Mesocrystal structure with the uniform crystal orientation shows special properties in electrocatalysis. Herein, PtRu mesocrystal was synthesized on F doped graphene by wet chemical method. In this reaction system, silicon nanowires and hydrofluoric acid were used to form Si - H bonds, which served as reducing agents to reduce Pt and Ru ions and grow PtRu particles on reduced graphene oxide (rG0). The electrochemical results showed that the PtRu/rGO catalyst had a favourable electrocatalytic performance on methanol oxidation reaction. The corresponding mass activity reached 739 mA mg(pt)(-1), which was 2.23 times as large as 20% commercial platinum carbon (Pt/C, 332 mA mg(pt)(-1)). Its stability and toxicity resistance were also much better than those of commercial Pt/C, showing a great prospect in practice applications. Furthermore, the forming mechanism of PtRu mesocrystal is discussed, which has general implications for the design of superstructure catalysts. (C) 2019 Elsevier Inc. All rights reserved.