Polarized Metal Nitride Solid Solutions as Electrocatalysts Enabling Ampere-Level Selective Formic Acid Synthesis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Formic acid (FA) is a valuable product from biomass electrooxidation, serving as a fuel and hydrogen carrier.
• Efficient industrial-scale synthesis of FA with stable hydrogen evolution remains a significant challenge.

Purpose of the Study:

• To develop a novel catalyst for efficient and selective formic acid synthesis via biomass electrooxidation.
• To investigate the role of atomic-level structural modifications in enhancing catalytic activity and stability.

Main Methods:

• Synthesis of a single-phase NiCoN solid-solution metal nitride catalyst.
• Characterization of the catalyst's structure and electronic properties.
• Electrochemical testing in an anion-exchange membrane (AEM) electrolyzer using glycerol as a co-reactant.

Main Results:

• The NiCoN catalyst, with atomic-level Co incorporation, created polarized active sites and optimized intermediate adsorption.
• This led to accelerated dehydrogenation kinetics and lower C-C bond cleavage energy barriers, favoring FA production.
• Achieved 97.2% FA Faradaic efficiency and over 3,600 hours of stable operation at 1 A cm-2.

Conclusions:

• Atomic-scale solid-solution engineering in NiCoN catalysts effectively regulates catalytic pathways for selective FA synthesis.
• The developed catalyst demonstrates exceptional long-term interfacial stability for biomass electrochemical conversion.
• This approach provides a promising strategy for advancing sustainable formic acid production.