Unambiguous hydrogenation of CO2 by coinage-metal hydride anions: an intuitive idea based on in silico experiments

Phys Chem Chem Phys. 2019 Apr 3;21(14):7483-7490. doi: 10.1039/c9cp00133f.

Abstract

Gas phase hydrogenation of CO2 to HCO2- by coinage-metal hydride anions, MH- (M = Cu, Ag and Au), has been studied with the help of high level computational methodologies. We demonstrate that these hydride anions perform excellently in the specific hydrogenation of CO2 to HCO2-. More precisely, AgH- is shown to be very active for this particular purpose. We show that CO2 activation through the M-HCO2 pathway passes through a very low energy barrier and produces HCO2-; even the metal centered activation (H-MCO2) also leads to the same product through an energy barrier less than 15 kcal mol-1. A closer inspection demonstrates that electronegativity, size of the metal and hydricity of the MH- species control the overall hydrogenation process.