Atomically dispersed Co-based species containing electron withdrawing groups for electrocatalytic oxygen reduction...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Single-atom catalysts offer unique advantages by combining molecular catalyst properties with conductive supports.
• Developing efficient catalysts for the oxygen reduction reaction (ORR) is crucial for energy conversion technologies.

Purpose of the Study:

• To synthesize and characterize a novel hybrid material (CoF/NG) for electrocatalytic applications.
• To investigate the electrocatalytic performance of the CoF/NG hybrid for the oxygen reduction reaction (ORR).

Main Methods:

• Low-temperature synthesis of a CoF/NG hybrid material from an organometallic complex (CoF) and N-doped reduced graphene oxide (NG).
• Microscopic and chemical characterization techniques to determine the structure and dispersion of Co species.
• Electrochemical measurements to evaluate the ORR activity and stability of the CoF/NG catalyst.

Main Results:

• Co-based species were found to be molecularly dispersed and coordinated to N sites on the NG surface.
• The CoF/NG hybrid exhibited enhanced ORR onset potential (0.91 V) and half-wave potential (0.80 V) compared to NG.
• Co-(N)graphene species were identified as the primary active sites for ORR, though nanoparticle formation reduced stability after cycling.

Conclusions:

• The incorporation of Co-based organometallic species with electron-withdrawing groups onto graphene networks boosts ORR performance.
• While enhancing electrocatalytic activity, these modifications lead to decreased stability of the active catalytic sites.