▎ 摘　　要

Oxygen reduction reaction (ORR) is crucial to energy conversion technologies such as fuel cells and metal-air batteries. Three-dimensional (3D) heteroatom-doped graphene-based materials have been reported to be efficient electrocatalysts for ORR in fuel cells for energy conversion. In this study, a novel cobalt-embedded nitrogen-doped graphene xerogel (denoted as Co-NGX) was prepared by a facile one-step hydrothermal method. The Co-NGX hybrid obtained at the pyrolysis temperature of 900 A degrees C (labeled as Co-NGX 900) was comparable to the benchmark Pt/C catalyst in terms of the onset potential and half-wave potential, indicating excellent ORR activity of our Co-NGX 900 catalyst. Additionally, the proposed Co-NGX 900 also displayed higher stability and better methanol tolerance than the commercial Pt/C, which might hold great promise as a Pt-free catalyst for application in alkaline direct methanol fuel cells (DMFCs). An advanced and highly efficient oxygen reduction reaction activity catalyst was synthesized by embedding cobalt nanocrystals in nitrogen-doped graphene xerogel.