High-throughput screening of metal-porphyrin-like graphenes for selective capture of carbon dioxide

TL;DR

This study uses high-throughput first principles thermodynamics to identify metal-porphyrin-like graphenes with empty d orbitals as highly selective and efficient materials for capturing CO₂ from flue gases at low pressures.

Contribution

It introduces a novel high-throughput screening method based on first principles to discover CO₂ capture materials with specific electronic properties, particularly empty d orbitals.

Findings

Elements with empty d orbitals selectively attract CO₂ at low pressures.

CO₂ binds via hybridization of metal d orbitals with CO₂ π orbitals.

Predicted new materials with high selectivity and capacity for CO₂ capture.

Abstract

Nano-materials, such as metal-organic frameworks, have been considered to capture CO$_2$. However, their application has been limited largely because they exhibit poor selectivity for flue gases and low capture capacity under low pressures. We perform a high-throughput screening for selective CO$_2$ capture from flue gases by using first principles thermodynamics. We find that elements with empty d orbitals selectively attract CO$_2$ from gaseous mixtures under low CO$_2$ pressures at 300 K and release it at ~450 K. CO$_2$ binding to elements involves hybridization of the metal d orbitals with the CO$_2$ $\pi$ orbitals and CO$_2$-transition metal complexes were observed in experiments. This result allows us to perform high-throughput screening to discover novel promising CO$_2$ capture materials with empty d orbitals and predict their capture performance under various conditions. Moreover, these findings provide physical insights into selective CO$_2$ capture and open a new path to explore CO$_2$ capture materials.