Partially Pyrolyzed Binary Metal-Organic Framework Nanosheets for Efficient Electrochemical Hydrogen Peroxide...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Electrochemical synthesis of hydrogen peroxide (H₂O₂) is a promising green chemistry approach.
• Metal-Organic Frameworks (MOFs) offer tunable structures for catalysis.
• Controlling nanoparticle distribution within MOFs is key to enhancing catalytic performance.

Purpose of the Study:

• To develop a partially controlled pyrolysis strategy for creating NiO nanoparticles within NiFe-MOF nanosheets.
• To investigate the use of these materials for electrochemical H₂O₂ synthesis via the two-electron oxygen reduction reaction (ORR).
• To optimize the material structure for high catalytic activity and selectivity.

Main Methods:

• Partially controlled pyrolysis of NiFe-MOF nanosheets (MOF NSs) to form NiO nanoparticles.
• Characterization of the resulting nanostructure (MOF NSs-300).
• Electrochemical evaluation of MOF NSs-300 for H₂O₂ production using ORR in KOH solution.

Main Results:

• Uniform distribution of NiO nanoparticles achieved on MOF NSs through partial pyrolysis.
• Optimized MOF NSs-300 exhibited near-zero overpotential and 99% selectivity for H₂O₂ production.
• A high H₂O₂ yield rate of 6.5 mol g_cat⁻¹ h⁻¹ was achieved at 0.6 V vs. RHE.

Conclusions:

• Partially pyrolyzed MOF NSs-300, with retained MOF structure and NiO nanoparticles, significantly enhances ORR performance.
• The synergy between MOF structure and NiO nanoparticles creates coordinatively unsaturated Ni atoms, boosting electrochemical H₂O₂ synthesis.
• This strategy offers an efficient pathway for producing H₂O₂ electrochemically.