A free energy landscape of the capture of CO2 by frustrated Lewis pairs

TL;DR

This study uses advanced simulations to analyze how frustrated Lewis pairs capture CO2, revealing that Lewis acids play a more critical role than Lewis bases in the process.

Contribution

It provides new insights into the individual roles of Lewis acids and bases in CO2 capture by FLPs using DFT-based metadynamics simulations.

Findings

Lewis acids are more important than Lewis bases in CO2 capture.

Lewis acids govern kinetic and thermodynamic aspects of the reaction.

Lewis bases mainly contribute to FLP formation.

Abstract

Frustrated Lewis pairs (FLPs) are known for its ability to capture CO2. Although many FLPs have been reported experimentally and several theoretical studies have been carried out to address the reaction mechanism, the individual roles of Lewis acids and bases of FLP in the capture of CO2 is still unclear. In this study, we employed density functional theory (DFT) based metadynamics simulations to investigate the complete path for the capture of CO2 by tBu3P/B(C6F5)3 pair, and to understand the role of the Lewis acid and base. Interestingly, we have found out that the Lewis acids play more important role than Lewis bases. Specifically, the Lewis acids are crucial for catalytical properties and are responsible for both kinetic and thermodynamics control. The Lewis bases, however, have less impact on the catalytic performance and are mainly responsible for the formation of FLP systems. Based on these findings, we propose a thumb of rule for the future synthesis of FLP-based catalyst for the utilization of CO2.