Reduced graphene oxide supported chromium oxide hybrid as high efficient catalyst for oxygen reduction reaction

•Cr2O3, which is usually adopted as ceramic material, is doped as catalyst for oxygen reduction.•Transitional metal oxide with low cost and rich sources is employed as catalysts for oxygen reduction.•4-electron style oxygen reduction reaction is observed with the catalysis of Cr2O3.

Reduced graphene oxide (rGO) supported nano-chromium oxide (Cr2O3/rGO) catalyst for oxygen reduction reaction (ORR) has been successfully synthesized by the pyrolysis of chromium-urea coordination compound. The structure and morphology of the hybrid are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) tests. XRD tests reveal that the Cr2O3 with hexagonal structure is obtained. SEM and TEM tests show that the nano-Cr2O3 is supported by rGO sheet. The cyclic voltammetry, tafel, linear scanning voltammetry and current-time chronoamperometric tests prove that the obtained Cr2O3/rGO hybrid has a remarkable catalytic activity and good stability for oxygen reduction. Both the rotating disc electrode and rotating ring disc electrode tests approve that the ORR major happens through 4-electron reaction style. The Cr2O3/rGO hybrid is a promising low cost and high performances catalyst for ORR of alkaline electrolyte.