MnO Enabling Highly Efficient and Stable Co-Nx/C for Oxygen Reduction Reaction in both Acidic and Alkaline Media

In situ growing transition metals on N-doped carbon by atomic doping produces a class of promising alternatives to replace Pt-based catalysts for redox reactions, yet still suffer from unsatisfactory activity and durability in acidic and basic media. Herein, a simple synthetic strategy to fabricate an MnO modifying Co-N-x/C catalyst with high activity and robust durability is presented. The interphase engineering well controls the Co and N species in the carbon matrix, affording the material with more pyridine N and graphite N; the interaction between Co-N-x and MnO phase is also well discussed. Accordingly, the obtained Co-N-x/C-MnO catalyst exhibits excellent electrocatalytic properties towards oxygen reduction reaction, achieving a half-wave potential of 0.87 and 0.66 V versus reversible hydrogen electrode in 0.1 m KOH and 0.1 m HClO4 solutions, as well as excellent durability with only -16.9 and -12.2 mV shift after 1000 cycles, respectively. This study provides insights into the design of noble-metal-free electrocatalysts from the perspective of active sites and catalyst carriers.

Automated summary

In situ growing transition metals on N-doped carbon by atomic doping presents a potential alternative to replace Pt-based catalysts for redox reactions. This study presents a simple synthetic strategy to fabricate a highly active and durable MnO modifying Co-N-x/C catalyst. The interphase engineering effectively controls the composition of the material, and the interaction between Co-N-x and MnO phase is also discussed. The resulting catalyst exhibits excellent electrocatalytic properties and durability in acidic and basic solutions.