Accelerating C─C Coupling Kinetics in Electrocatalytic CO₂ Reduction by Precisely Atomic Cu₆ Cluster with...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Improving carbon dioxide electroreduction (CO2RR) performance hinges on strengthening carbon-carbon coupling via tailored copper-copper (Cu-Cu) sites.
• Unstable Cu sites complicate reaction pathways and intermediates in CO2RR.

Purpose of the Study:

• To investigate the relationship between Cu site vibratility and CO2RR performance.
• To design and synthesize iodine-bridged atomic clusters with varying Cu site vibratility.

Main Methods:

• Construction of Cu6 polymorphic isomers, specifically trigonal (T-Cu6I6) and cubic (C-Cu6I6) clusters.
• In situ spectroscopic characterizations and theoretical calculations.
• Electrochemical performance evaluation for CO2RR.

Main Results:

• Trigonal Cu6 clusters (T-Cu6I6) with low vibratility (1.5%) exhibited a more stable structure compared to cubic clusters (C-Cu6I6, 25% vibratility).
• T-Cu6I6 achieved a significantly higher Faradaic efficiency for C2 products (78%) than C-Cu6I6 (41%).
• Slightly vibrative Cu sites in T-Cu6I6 facilitate *CO protonation and C-C coupling.

Conclusions:

• Site vibratility is a critical factor influencing CO2RR electrocatalytic performance.
• Stable, slightly vibrative Cu sites accelerate reaction kinetics, enhancing C2 product selectivity.
• This work offers a strategy for tuning electrocatalytic activity by controlling atomic cluster vibratility.