Steering carbon dioxide electroreduction toward formic acid by Sn-induced Cu⁰ stabilization and optimized *OCHO...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical CO2 reduction (eCO2RR) to formic acid (HCOOH) offers sustainable carbon utilization.
• Copper-based catalysts face challenges with low selectivity and poor stability.
• The role of stable Cu0 in eCO2RR selectivity is underexplored.

Purpose of the Study:

• To stabilize metallic Cu0 against dissolution during eCO2RR using tin (Sn) doping.
• To investigate the electronic structure modifications and their impact on CO2 adsorption and reaction pathways.
• To develop a durable and selective copper-based catalyst for HCOOH production.

Main Methods:

• Doping copper (Cu) with tin (Sn) using magnetron sputtering.
• Electrochemical characterization to assess catalyst performance (Faradaic efficiency, current density).
• Analysis of electronic structure and intermediate adsorption configurations.

Main Results:

• Sn doping stabilizes Cu0, modifying electronic structure and CO2 adsorption.
• Enhanced *OCHO adsorption over *COOH, favoring HCOOH pathway.
• Optimized Cu50Sn20 catalyst achieved 81% Faradaic efficiency for HCOOH at -1.0 V RHE.
• Catalyst demonstrated negligible degradation over 40 hours of continuous operation.

Conclusions:

• Stabilizing metallic states is crucial for designing effective eCO2RR catalysts.
• Tin doping provides a novel strategy for enhancing the durability and selectivity of copper-based catalysts.
• This approach enables efficient and sustainable production of HCOOH from CO2.