Enhancing Localized Electron Density over Pd_1.4Cu Decorated Oxygen Defective TiO_2-x Nanoarray for Electrocatalytic...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrite reduction to ammonia is crucial for pollution control and industrial synthesis.
• Current limitations include inefficient catalysts and unclear reaction mechanisms.

Purpose of the Study:

• To develop an efficient and selective catalyst for nitrite reduction to ammonia.
• To elucidate the catalytic mechanism using in situ/operando studies and DFT calculations.

Main Methods:

• Loading Palladium-Copper (PdCu) alloy onto oxygen-defective Titanium Dioxide (TiO2-x).
• Utilizing in situ and operando spectroscopic studies.
• Performing Density Functional Theory (DFT) calculations.

Main Results:

• Achieved a significant increase in ammonia yield (70.6 to 366.4 µmol cm⁻² h⁻¹ at -0.6 V).
• Demonstrated excellent selectivity and stability over 50 hours.
• DFT revealed PdCu alloys enhance electron density at oxygen vacancies, facilitating nitrite adsorption and activation.

Conclusions:

• Modulating localized electron density via PdCu alloy loading on TiO2-x is key for efficient ammonia synthesis.
• The mechanism involves gradual deoxygenation and hydrogenation facilitated by oxygen vacancies and the alloy.
• This approach provides valuable insights for sustainable ammonia production.