Concurrent H₂ Generation and Formate Production Assisted by CO₂ Absorption in One Electrolyzer

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Electrolyzers offer reduced voltage and high-value products by coupling hydrogen evolution with organic molecule oxidation.
• Simultaneous CO2 capture and conversion alongside hydrogen production is crucial for sustainable energy solutions.

Purpose of the Study:

• To design and optimize an electrolyzer for simultaneous hydrogen generation, CO2 absorption, and methanol upgrading.
• To utilize low-cost transition metal phosphides as catalysts for these integrated processes.

Main Methods:

• Development of a unique electrolyzer configuration.
• Catalyst screening and optimization using transition metal phosphides.
• Electrochemical performance testing across various current densities.

Main Results:

• Achieved a low working voltage of 1.1 V at 10 mA cm⁻².
• Demonstrated nearly 100% Faraday efficiencies for hydrogen evolution and formic acid conversion.
• Observed CO2 absorption rates approximately double the hydrogen generation rate, nearing theoretical values.

Conclusions:

• The developed electrolyzer efficiently integrates hydrogen production, CO2 capture, and methanol valorization.
• Low-cost transition metal phosphide catalysts enable an innovative and energy-efficient approach.
• This strategy presents a promising pathway for simultaneous hydrogen generation and CO2 management.