Noble-metal-free electrocatalysts with enhanced ORR performance by task-specific functionalization of carbon using...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for the oxygen reduction reaction (ORR) is crucial for energy conversion technologies.
• Current state-of-the-art catalysts, such as platinum, face challenges related to cost and stability.

Purpose of the Study:

• To synthesize and characterize novel functionalized carbon hybrids with variable heteroatom doping profiles.
• To evaluate the electrocatalytic activity and stability of these materials for the ORR in different electrolytes.

Main Methods:

• Synthesis of nitrogen-doped and N-S, N-P, N-B codoped carbon hybrids from nitrile-functionalized ionic precursors using ferric chloride.
• Characterization using X-ray photoelectron spectroscopy (XPS).
• Electrochemical evaluation of ORR activity and stability in alkaline and acid electrolytes.

Main Results:

• Successfully synthesized microporous carbon hybrids with tailored doping.
• Heteroatom doping (N, S, P, B) and iron significantly enhanced ORR electrocatalytic activity.
• Sulfur-nitrogen codoped carbon exhibited superior activity and stability compared to commercial Pt in alkaline media.
• Sulfur-nitrogen codoped catalyst demonstrated comparable activity and superior stability to Pt in acidic media.

Conclusions:

• The study presents a versatile method for creating advanced carbon hybrids with tunable doping for enhanced ORR performance.
• The unique atomic structure of N-S codoped carbon is key to its superior electrocatalytic properties.
• These functionalized carbon materials offer a promising alternative to precious metal catalysts for energy applications.