An ab initio study of the use of Ag2− for catalytic oxidation of CO

The formalisms of density functional theory (DFT) with Perdew and Wang exchange-correlation functional have been employed to study the electronic and geometric structures of silver anion dimer bonded with carbon monoxide and oxygen. Different possible structures for di-silver carbon monoxide and di-silver di-oxide have been investigated in detail. An all electron 6-311++G** basis set for carbon and oxygen and a pseudopotential basis set for silver have been used for performing the calculations. Using silver anion dimer as a catalyst, a full catalytic cycle producing two carbon dioxide molecules has been presented. Also, presence of an intermediate state, di-silver carbonate, which can be detected experimentally, is predicted. Presence of an energy barrier for certain reactions from the catalytic cycle have not been observed. This is noteworthy since it has been claimed in the literature that for the same catalytic cycle to proceed using gold anion dimer as a catalyst, it has to overcome an energy barrier.