Cooperative CO${}_2$ capture via oxalate formation on metal-decorated graphene

Abstract

CO${}_2$ capture using carbon-based materials, particularly graphene and graphene-like materials, is a promising strategy to deal with CO${}_2$ emissions. However, significant gaps remain in our understanding of the molecular-level interaction between CO${}_2$ molecules and graphene, particularly, in terms of chemical bonding and electron transfer. In this work, we employ random structure search and density functional theory to understand the adsorption of CO${}_2$ molecules on Ca, Sr, Na, K, and Ti decorated graphene surfaces. Compared to the pristine material, we observe enhanced CO${}_2$ adsorption on the decorated graphene surfaces. Particularly on group 2 metals and titanium decorated graphene, CO${}_2$ can be strongly chemisorbed as a bent CO${}_2$ anion or as an oxalate, depending on the number of CO${}_2$ molecules. Electronic structure analysis reveals the adsorption mechanism to involve an ionic charge transfer from the metal adatom to the adsorbed CO${}_2$. Overall, this study suggests that reducing CO${}_2$ to oxalate on group 2 metals and titanium metal-decorated graphene surfaces is a potential strategy for CO${}_2$ storage.

arXiv commentMain manuscript and Supplementary information provided

References in corpus (9)

• The Raman Fingerprint of Graphene
• Graphene: Status and Prospects
• Van der Waals density functionals applied to solids
• Ab initio Random Structure Searching
• Titanium-decorated carbon nanotubes: a potential high-capacity hydrogen storage medium
• SCAN+rVV10: A promising van der Waals density functional
• Properties of the water to boron nitride interaction: from zero to two dimensions with benchmark accuracy
• Ground-State Structures of Ice at High-Pressures
• Mechanisms of adsorbing hydrogen gas on metal decorated graphene