Co₂P as a pre-catalyst: enhancing NO₃RR activity by controlled surface activation

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Nitrate electroreduction is a key process for nitrogen management and sustainable chemical synthesis.
• Developing efficient electrocatalysts for neutral nitrate reduction remains a significant challenge.

Purpose of the Study:

• To investigate cobalt phosphide (Co2P) nanorods as precatalysts for neutral nitrate electroreduction.
• To understand the surface transformations of Co2P during electrocatalysis.

Main Methods:

• Synthesis of Co2P nanorods.
• Electrochemical characterization of nitrate reduction.
• In-situ surface analysis techniques to probe the catalyst surface.

Main Results:

• Co2P nanorods function as dynamic precatalysts, undergoing surface changes during the reaction.
• Controlled hydroxylation followed by electroreduction generates a reduced, cobalt-rich surface.
• The phosphide framework is maintained during the transformation, ensuring catalyst stability.

Conclusions:

• Surface reconstruction plays a crucial role in the catalytic activity of Co2P for nitrate electroreduction.
• The dynamic nature of the precatalyst allows for the formation of a highly active Co-rich surface under operating conditions.