Efficient Tetra-Functional Electrocatalyst with Synergetic Effect of Different Active Sites for Multi-Model Energy...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The global energy crisis and climate change necessitate efficient CO2 conversion and renewable energy solutions.
• Developing multifunctional electrocatalysts is crucial for advancing technologies like CO2 reduction, metal-air batteries, and water splitting.

Purpose of the Study:

• To design and synthesize a novel, multifunctional electrocatalyst for CO2 reduction reaction (CO2RR), oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER).
• To evaluate the electrocatalyst's performance in a dual model CO2/air battery and water electrolyzer system.

Main Methods:

• Fabrication of a composite electrocatalyst integrating CoNi nanoalloy, N-doped carbon nanotubes, and single atomic Ni sites.
• Electrochemical characterization of the catalyst for CO2RR, ORR, OER, and HER in various electrolyte conditions.
• Testing the catalyst's performance in a custom-built CO2/air battery and water splitting electrolyzer.

Main Results:

• Achieved high Faradaic efficiency (FE) of 99% for CO2RR in 0.5 M KHCO3.
• Demonstrated superior ORR activity compared to Pt/C with a more positive onset potential (0.98 V) and half-wave potential (0.86 V).
• Exhibited low overpotentials for OER (η10 = 250 mV) and HER (η10 = 49 mV), achieving the lowest reported ORR/OER potential gap (0.62 V) and water splitting cell bias (1.57 V).

Conclusions:

• The developed CoNi-based electrocatalyst exhibits remarkable multifunctional performance for key energy conversion reactions.
• This work presents a promising strategy for designing advanced electrocatalysts for sustainable energy applications.
• The catalyst's effectiveness in practical battery and electrolyzer systems highlights its potential for clean energy technologies.