Capture and Reaction of CO2 and H2 Catalyzed by a Complex of Coronene: A Computational Study

Abstract

An organometallic complex of coronene (Cor) and chromium (Cr) was designed and used as a catalyst in a simulated process in which a CO2 molecule is captured, activated, and then reacts with a hydrogen molecule (H2) to yield formic acid (HCOOH). The structural characteristics and local aromaticity are due to the similarity in the binding scheme with the bis(benzene)chromium (Cr-Bz2). Such a molecular fragment, referred to here as a “Clar’s site”, involves a single chromium atom that binds to CO2 by transferring electron density through backdonation. Therefore, the capture of CO2 outside the Cr3-Cor2 complex allows for the carrying out of a hydrogenation process that involves the breaking of one of the C−O bonds, the double addition of hydrogen, the formation of HCOOH and its release, regenerating the structure of the Cr3-Cor2 complex. The thermodynamic and kinetic results of this reaction are analyzed, as well as the nature of the orbitals and the relevant interactions of this process. This work explores a new concept for the creation of single atom catalysts (SACs), taking advantage of the high electron density around the metallic center and the sandwich architecture, having shown that it can perform the catalytic reduction of CO2.