Carbon monoxide-resistant copper-cobalt nanocrystal@ nitrogen-doped carbon electrocatalysts for methanol oxidation reaction

•Cu-Co alloy nanocrystals are stabilized in a nitrogen-doped carbon matrix to form Cu-Co@N-C.•The charge transfer from Co to Cu enhanced the oxidative activity of Co for MOR.•The highly porous N-C matrix facilitates the mass and charge transfer.•The MOR activity of Cu-Co@N-C is higher than most of Cu and Co-based MOR catalysts. [Display omitted] The performance of direct methanol fuel cells (DMFC) mainly depends on the activity and stability of the noble-metal-based anode catalysts for methanol oxidation reaction (MOR), whose broad application is limited by the scarcity of noble metals and their susceptibility to carbon monoxide poisoning. Many efforts have been devoted to the developing of non-noble metal based MOR catalysts. Previous studies have shown that the catalytic properties of noble-metal catalysts can be modified by alloying in nanomaterials. However, non-noble metal-based nanocrystals are rarely studied as electrocatalysts, because of their high susceptibility to air oxidation. Herein, we report a simple strategy to prepare non-noble metal nanocrystals (Cu-Co nanocrystals), which are stabilized in a nitrogen-doped carbon (N-C) matrix to form Cu-Co@N-C composite. Since Co has a high activity for oxidation reactions, and Cu has a high adsorption capacity for methanol, the Cu-Co nanocrystals should present good MOR activity because of the synergistic effect of Cu and Co. The highly active Cu-Co nanocrystals are embedded in a porous N-C matrix with a large specific surface area (127.3 m2/g), which not only protects the Cu-Co nanocrystals, but also facilitate the mass and charge transfer. Indeed, the optimal Cu-Co@N-C catalyst shows a MOR activity of 171.3 mA/cm2 at 0.6 V vs SCE in alkaline medium, which is higher than most of previously reported Cu and Co-based MOR catalysts. The stability and CO-resistance of the optimal Cu-Co@N-C catalyst are also better than that of Pt/C catalyst, enabling Cu-Co@N-C a promising MOR catalyst for broad application of DMFC.