Highly Conductive and CO‐Resistant Cobalt‐Based Monolithic Electrodes for the Catalytic Oxidation of Methanol

Abstract

AbstractTo develop active and stable electrocatalysts for the methanol oxidation reaction (MOR), many non‐noble metal‐based nanomaterials have been explored, which are physically loaded on conductive substrates to form electrodes. During a long‐term MOR under high current density, these electrodes usually lose activity due to the aggregation or falling off of active nanomaterials. To overcome these problems, we report a simple strategy to synthesize an active, stable, and carbon monoxide (CO)‐resistant monolithic electrode for the MOR: cobalt nanocrystal/nitrogen, oxygen‐doped carbon (Co@N,O−C, CP) monolith. CP monolith shows a high electrical conductivity (1.54×104 S/cm), which can be directly used as an electrode without any substrate. Co nanocrystals are dispersed uniformly in the N,O−C matrix as the active site for MOR, whereas the N,O−C matrix protects Co nanocrystals and also facilitates the mass and charge transfer between electrolyte and the electrode. The optimized CP−FT‐500 electrode presents a high MOR activity of 352 mA/cm2 at 0.6 V vs SCE (unsaturated calomel electrode) in alkaline electrolyte, which exceeds most previously reported Co‐based MOR catalysts. The optimal CP−FT‐500 catalyst also presents excellent durability and anti‐CO poisoning capability (93.3 % retention of activity), which exceeds that of Pt/C (67.5 % retention). Based on its excellent catalytic activity, stability, and high resistance to CO poisoning, CP−FT‐500 catalyst is a promising low‐cost catalyst for MOR.