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Related Experiment Video

Updated: Sep 20, 2025

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

Published on: November 9, 2019

Steric-Dominated Intermediate Stabilization by Organic Cations Enables Highly Selective CO₂ Electroreduction.

Zishan Han^1,2, Xinyu Wang¹, Zhiguo Li¹

¹Nanoyang Group, Tianjin Key Laboratory of Advanced Carbon and Electrochemical Energy Storage, School of Chemical Engineering and Technology, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072, China.

Angewandte Chemie (International Ed. in English)

|May 28, 2025

Summary

This study introduces a novel steric-effect strategy using organic quaternary ammonium cations to enhance electrocatalytic CO2 reduction. This method improves selectivity for formic acid production by tuning intermediate adsorption on copper surfaces.

Keywords:

Adsorption Cations Copper Electrochemistry

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Published on: November 27, 2015

Area of Science:

Electrochemistry
Materials Science
Catalysis

Background:

Controlling intermediate binding energies is crucial for selective electrocatalytic CO2 reduction (CO2RR).
Alkali cations are known to stabilize intermediates via electrostatic interactions.
A steric-effect-dominated strategy using organic cations offers a new approach to tune intermediate adsorption.

Purpose of the Study:

To investigate the use of organic quaternary ammonium cations (CnTA+) for modulating intermediate adsorption in CO2RR.
To elucidate the mechanism by which these cations influence reaction pathways.
To improve the selectivity and efficiency of formic acid production.

Main Methods:

In-situ attenuated total reflectance-surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) to study cation behavior at the electrode surface.
Electrocatalytic CO2 reduction experiments using copper electrodes modified with different CnTA+ cations.
Analysis of Faradaic efficiency (FE) for formic acid production.

Main Results:

Longer alkyl chain CnTA+ cations exhibit higher affinity for the copper surface and more efficiently substitute alkali cations in the electrical double layer.
Steric effects of CnTA+ cations significantly enhance the adsorption of key reaction intermediates.
Octadecyl trimethyl ammonium (C18TA+) cations led to a formic acid FE of up to 90%.

Conclusions:

Organic quaternary ammonium cations, particularly those with longer alkyl chains, can effectively steer the CO2RR pathway toward formic acid via a steric-effect-dominated mechanism.
This molecular engineering approach provides a flexible route to optimize CO2RR performance.
The findings offer a new strategy for designing advanced electrocatalysts for CO2 conversion.