Nitrogen-Doped Mesoporous Graphene as a Synergistic Electrocatalyst Matrix for High-Performance Oxygen Reduction Reaction

Abstract

To balance the anchoring sites and conductivity of the catalyst supports is a dilemma in electrocatalytic oxygen reduction reaction (ORR). Nitrogen-doped mesoporous graphene (N-MG) with large surface area, high porosity, and superior intrinsic conductivity has been developed to address this issue. Using N-MG as the backbone, a hybrid catalyst of Co3O4 nanocrystals embedded on N-MG (Co3O4/N-MG) was prepared for the electrocatalytic ORR in alkaline media. The Co3O4/N-MG showed high catalytic activity for the four-electron ORR, giving a more positive onset potential (0.93 V vs RHE) and a higher current density. The unique property of N-MG and the synergetic effect of Co3O4 and N-MG are prominent for ORR. With improved electrocatalytic activity and durability, the Co3O4/N-MG can be an efficient nonprecious metal catalyst and potentially used to substitute the platinum-based cathode catalysts in fuel cells and metal-air batteries.

Co3O4 nanoparticles anchored on nitrogen-doped reduced graphene oxide as a multifunctional catalyst for H2O2 reduction, oxygen reduction and evolution reaction

“…2D, suggesting there is no Co 3 O 4 particles nucleate on N-rGO surface. The oxygen-containing functional groups of rGO were beneficial for the nucleation and anchoring of nanocrystals on the sheets to achieve covalent attachments, which help to shape the uniform formation of Co 3 O 4 3536. In addition, these uniform structures of Co 3 O 4 particles anchored into N-rGO can also be ascribed to NH 3 together with oxygen-containing functional group coordinating with cobalt cations and thus reducing Co 3 O 4 particles size and enhancing particles nucleation on N-rGO37.…”

Nitrogen-Doped Carbon Nanotube and Graphene Materials for Oxygen Reduction Reactions

“…The improved performance can be attributed to the synergetic effects between NG and alloy nanostructures. There are also a number of similar reports using non-precious metal to produce metal/NG composites, showing potential applications [132][133][134][135][136]. [131].…”

Design and Application of Foams for Electrocatalysis

“…ORR process commonly occurs through two different types: one is the efficient four‐electron, one‐step pathway and the other is inefficient two‐electron, two‐step pathway. The sluggish kinetics of ORR dramatically limits the energy conversion efficiency of fuel cells and metal‐air batteries . Till now, Pt‐ and Pt alloys‐based materials are identified as the state‐of‐the‐art catalysts to drive the inherently sluggish ORR .…”