▎ 摘　　要

A novel composite catalyst based on in situ synthesis of W1+49 nanorods on reduced graphene oxide sheets was successfully fabricated through a one-pot solvothermal route. The as-prepared W18O49-reduced graphene oxide (rGO) composite has been systematically characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman microscopy, X-ray photoelectron spectra, and a rotating disk electrode. Compared to W18O49 nanorods or reduced graphene oxide alone, or their physical mixture, the composite catalyst exhibited unexpectedly high ORR activity with a more positive onset-potential (close to that of Pt/C) and a higher kinetic current density (J(K)), which is mainly attributed to the nanorod morphology, surface oxygen vacancies of W18O49, and strong coupling interaction between the W18O49 nanorods and reduced graphene oxide sheets. These results raise the possibility of developing low-cost and efficient ORR electrocatalysts.