Engineering Amorphous/Crystalline Ni/NiO Electrocatalysts for Highly Efficient Hydrogen Peroxide Production.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrochemical hydrogen peroxide production (EHPP) relies on enhanced O2 adsorption and favorable oxygen-intermediate desorption during the two-electron oxygen reduction reaction (2e- ORR).
• Developing advanced electrocatalysts is crucial for optimizing these processes.

Purpose of the Study:

• To report an amorphous/crystalline Ni-NiO electrocatalyst synthesized via a partial reduction strategy for EHPP.
• To investigate the effect of interfacial strain on catalyst performance.

Main Methods:

• Synthesis of amorphous/crystalline Ni-NiO electrocatalyst through partial reduction.
• Engineering interfacial strain by varying reduction time.
• Performance evaluation using electrochemical measurements (selectivity, Faradaic efficiency, H2O2 yield).
• Computational modeling (Density Functional Theory) and in situ characterizations.

Main Results:

• Optimized Ni/NiO catalyst achieved 91.78% H2O2 selectivity and 97.47% Faradaic efficiency.
• High H2O2 yield of 949.5 mM/gcat-1 h-1 was maintained across three electrode systems.
• Strain at unsaturated Ni sites promoted O2 adsorption and weakened *OOH binding.
• In situ generated H2O2 demonstrated effectiveness in degrading organic pollutants.

Conclusions:

• Strain engineering in amorphous/crystalline Ni/NiO heterostructures is a viable approach for high-performance EHPP.
• The catalyst facilitates selective two-electron ORR by optimizing O2 adsorption and *OOH desorption.
• The developed catalyst shows practical utility in water remediation applications.