3d-Metal monocarbonyls MCO, MCO+, and MCO- (M=Sc to Cu): comparative bond strengths and catalytic ability to produce CO2 in reactions with CO

The electronic and geometrical structures of 3d-metal monocarbonyls MCO (M=Sc to Cu), the MCO- anions and MCO+ cations are computed using the density functional theory with generalized gradient approximation for the exchange-correlation potential. Our calculated adiabatic electron affinities and ionization potentials are in good agreement with experiment. Using the results of our previous computations on the MC, MC-, and MC+ series, we estimated the energies required for the Boudouard disproportionation reactions MCO0,-,++CO→MC0,-,++CO2. Among the neutrals, this reaction is endothermic by 1.30 eV for Mn, while Fe is found to be the second best atom, with the reaction being endothermic by 1.59 eV. These are substantially reduced with respect to the gas phase Boudouard reaction CO+CO→C+CO2, which is endothermic by 5.65 eV. Several of the anions have disproportionation energies similar to the neutrals, while cations are found to be less favorable than the neutrals