Spinel Mn-Co Oxide in N-Doped Carbon Nanotubes as a Bifunctionai Electrocatalyst Synthesized by Oxidative Cutting

摘要

The notorious instability of non-precious-metal catalysts for oxygen reduction and evolution is by far the single unresolved impediment for their practical applications. We have designed highly stable and active bifunctionai catalysts for reversible oxygen electrodes by oxidative thermal scission, where we concurrently rupture nitrogen-doped carbon nanotubes and oxidize Co and Mn nanoparticles buried inside them to form spinel Mn-Co oxide nanoparticles partially embedded in the nanotubes. Impressively high dual activity for oxygen reduction and evolution is achieved using these catalysts, surpassing those of Pt/C, RuO_2, and IrO_2 and thus raising the prospect of functional low-cost, non-precious-metal bifunctionai catalysts in metal-air batteries and reversible fuel cells, among others, for a sustainable and green energy future.