Steering CO₂ Electroreduction to C₂₊ Products via Enhancing Localized *CO Coverage and Local Pressure in Conical...

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrochemical carbon dioxide reduction (CO2RR) is complex due to multistep proton-coupled electron transfer (PCET) and intermediate formation.
• Achieving high activity and selectivity in CO2RR to target products remains a significant challenge.

Purpose of the Study:

• To design and investigate a novel catalyst with a nanosheet-stacked sphere structure featuring open and deep conical cavities (OD-CCs).
• To understand how controlling confinement space within the catalyst influences CO2RR intermediate behavior and product selectivity.

Main Methods:

• Synthesis of a catalyst with a unique nanosheet-stacked sphere structure and OD-CCs.
• Finite-element method (FEM) simulations and theoretical analysis to study reaction mechanisms.
• Electrochemical evaluation of the catalyst's performance in CO2RR.

Main Results:

• The OD-CCs in the catalyst create confined spaces that lead to diffusion limitations for carbon intermediates.
• This confinement increases local pressure and enhances localized CO coverage, promoting dimerization.
• The catalyst structure-driven approach significantly improved the selectivity for multicarbon (C2+) products from 41.8% to 81.7%.

Conclusions:

• Controlling catalyst nanostructure, specifically the confinement space in OD-CCs, is an effective strategy to enhance CO2RR performance.
• The developed catalyst demonstrates a significant structure-driven improvement in selectivity for valuable multicarbon products.
• This work offers insights into catalyst design for efficient electrochemical CO2 conversion.