MoC_x/CoP Janus Structure Embedded Carbon Frame for Boosting Hydrazine Oxidation and Hydrogen Evolution Reactions

Area of Science:

• Electrochemistry and Catalysis
• Materials Science
• Energy Conversion

Background:

• Efficient hydrogen production is crucial for clean energy.
• Integrating hydrazine electrooxidation (HzOR) and hydrogen evolution reaction (HER) offers a promising route for high-purity hydrogen.
• Developing bifunctional catalysts with multiple active sites and tailored electronic properties for both reactions remains a significant challenge.

Purpose of the Study:

• To design and synthesize a novel Janus nano-catalyst for efficient bifunctional electrocatalysis.
• To investigate the catalytic activity and mechanistic origins of dual active sites for hydrazine electrooxidation and hydrogen evolution reaction.
• To evaluate the performance of the catalyst in an overall hydrazine splitting system for hydrogen production.

Main Methods:

• Synthesis of MoC_x/CoP embedded on carbon frameworks (MoC_x/CoP@C) as Janus nano-catalysts.
• Theoretical analysis (e.g., DFT calculations) to understand charge redistribution and electronic properties.
• Electrochemical characterization including cyclic voltammetry, linear sweep voltammetry, and chronoamperometry to assess HER and HzOR performance.
• Evaluation in an overall hydrazine splitting (OHzS) system to determine energy consumption, Faradaic efficiency, and stability.

Main Results:

• The MoC_x/CoP@C catalyst exhibits dual electronic states (depletion and accumulation) and independent dual active sites (DAS) for HER and HzOR.
• Theoretical analysis confirmed enhanced catalytic activity due to charge redistribution, weakening N-H bonding for HzOR and accelerating H* desorption for HER.
• The catalyst demonstrated ultra-low potential (-73 mV at 10 mA cm^-2) for HzOR and low overpotential (95 mV at 10 mA cm^-2) for HER.
• In an overall hydrazine splitting system, MoC_x/CoP@C achieved low energy consumption (0.16 V), high Faradaic efficiency (95.4%), and excellent long-term stability.

Conclusions:

• The developed Janus nano-catalyst MoC_x/CoP@C effectively integrates HzOR and HER functionalities.
• Independent dual active sites arising from tailored electronic properties are key to the enhanced bifunctional catalytic performance.
• This study highlights a viable strategy for designing advanced bifunctional catalysts for efficient and sustainable hydrogen production.