Electron Sponge Effect by Dynamic-Regulated Electron Self-Flow toward Coupled Electrochemical Ammonia Synthesis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalysis is crucial for sustainable chemical synthesis and energy conversion.
• Developing efficient electrocatalysts for nitrogen reduction reaction (NRR) and oxygen evolution reaction (OER) remains a significant challenge.

Purpose of the Study:

• To construct a dynamic-regulated palladium-iron-nitrogen (Pd-Fe-N) electrocatalyst.
• To optimize electrocatalytic activity through electron-donating and back-donating effects.
• To elucidate the mechanism of the interstitial-N-dopant-induced electron sponge effect.

Main Methods:

• Synthesis of PdFe3/FeN electrocatalyst.
• Electrochemical measurements for NRR and OER.
• In situ attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR).
• X-ray absorption spectroscopy (XAS).
• Density functional theory (DFT) calculations.

Main Results:

• The PdFe3/FeN catalyst exhibited high performance for NRR (yield rate of 29.94 μg h⁻¹ mgcat⁻¹, FE of 38.43% at -0.2 V vs RHE) and OER (308 mV at 100 mA cm⁻²).
• The interstitial N dopant induced an electron sponge effect, enhancing N2 capture and NH3 desorption during NRR.
• Electron-deficient Fe sites facilitated FeOOH reconstruction, accelerating OER kinetics.

Conclusions:

• The dynamic-regulated Pd-Fe-N electrocatalyst demonstrates a promising strategy for optimizing electrocatalytic performance.
• The electron sponge effect plays a critical role in enhancing the NRR process.
• This work provides insights into advanced electrocatalyst design for efficient synthesis and energy storage.