Nitrogen Co-Doping into MnMOF Wrapped in Reduced Graphene Oxide (N-Mnmof@rgo): an Advanced Catalyst for Oxygen Reduction Reaction

Combing the Mn metal–organic frameworks (MnMOFs) actives with rational carbon-matrix support is an effective way to develop high-performance non-noble metal catalysts in fuel cells. Herein, a novel non-Pt cathodic catalyst for oxygen reduction reaction (ORR), nitrogen co-doping into MnMOF nanoparticles wrapped in the reduced graphene oxide (N-MnMOF@rGO), was designed and successfully synthesized. The two-dimensional layered rGO can not only stabilize the structure of MnMOF, but also improve the overall conductivity of the composite catalyst. Meanwhile, the N doping could provide more active sites and improve the catalytic activity. Benefiting from the advantageous nanostructures featured with extremely high specific surface area, enriched catalytic active sites, and enhanced electronic transportation, the obtained N-MnMOF@rGO catalyst exhibits good catalytic performance. ORR test results show that the onset potential and half-wave potential are 0.88 V and 0.76 V, higher than those of the pure MnMOF, respectively. Furthermore, a small loss of current density after consecutive 10,000 cycles and a high electron transferred number of 4.3 are confirmed, indicating excellent stability and fast reaction kinetics. All these results demonstrate that the obtained N-MnMOF@rGO can be considered a highly potential non-Pt catalyst for practical ORR application in requirement of low cost, high catalytic behavior, and excellent stability.