Gold Self-Assembly on Copper Electrodes Promotes n-Propanol Formation in Electrochemical CO₂ Reduction

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrochemical CO2 reduction (CO2RR) is a key technology for mitigating greenhouse gas emissions.
• Producing n-propanol via CO2RR is desirable due to its high energy density and industrial applications.
• Achieving high selectivity for n-propanol remains challenging due to complex reaction pathways.

Purpose of the Study:

• To develop a catalyst architecture for enhanced selectivity in n-propanol production via CO2RR.
• To investigate the role of self-assembled monolayers (SAMs) in catalyst design for CO2RR.
• To improve the Faradaic efficiency of n-propanol synthesis.

Main Methods:

• Fabrication of a Cu/Cys/Au catalyst using cysteamine SAMs on copper substrates.
• Uniform electrodeposition of gold facilitated by a Au3+-dimercaptosuccinate complex anchored by SAMs.
• Electrochemical evaluation of the catalyst performance for CO2RR at -1.2 V vs. RHE.

Main Results:

• The Cu/Cys/Au electrode achieved a Faradaic efficiency of 29.1% for n-propanol.
• Control studies confirmed the necessity of both Au and Cu for selective n-propanol formation.
• Tuning SAM composition allowed precise control over gold coverage on the copper surface.

Conclusions:

• SAM-based surface engineering provides a pathway for developing highly selective CO2RR electrocatalysts.
• The developed Cu/Cys/Au catalyst demonstrates significant potential for efficient n-propanol production.
• This strategy offers a promising approach for sustainable chemical synthesis from CO2.