부산대학교 도서관

Mitigation of CO2and its conversion into valuable chemicals is obligatory as continuous emission of CO2is a serious threat to global climate change and hence to living beings. Herein, we have studied the catalytic behavior of magic cluster Sn10O20toward the reduction of CO2to formic acid (FA) using the density functional theory (DFT) method. Two possible pathways have been explored for the conversion. First, the dissociation of H2on the cluster offers a route where Sn hydride triggers the selectivity of formic acid formation via a HCOO* intermediate. Second, in the coadsorption pathway, as a result of the polarization effects of the ‘O’ of the O2C4active site, H2gets activated and forms a stable six-membered ring in the transition state to give a direct HCOO* intermediate. In the transition state, the ‘H’ in the newly formed “C–H” bond is also characterized as a hydride with the Bader charge of −0.19 |e|, and it holds the selectivity of formic acid. Among the two pathways, the coadsorption pathway proves to have better catalytic efficiency by providing a lower energetic pathway than the Sn-hydride-assisted pathway. Our results and analyses reveal that the reduction pathway changes to get better selectivity from the small SnO2to the larger-sized Sn10O20. It is also noteworthy to mention that catalytic efficiency depends upon the coordination number of “Sn” in the clusters.