Converting CO(2) to formic acid by tuning quantum states in metal chalcogenide clusters

The catalytic conversion of CO(2) into valuable chemicals is an effective strategy for reducing its adverse impact on the environment. In this work, the formation of formic acid via CO(2) hydrogenation on bare and ligated Ti(6)Se(8) clusters is investigated with gradient-corrected density functional theory. It is shown that attaching suitable ligands (i.e., PMe(3), CO) to a metal-chalcogenide cluster transforms it into an effective donor/acceptor enabling it to serve as an efficient catalyst. Furthermore, by controlling the ratio of the attached donor/acceptor ligands, it is possible to predictably alter the barrier heights of the CO(2) hydrogenation reaction and, thereby, the rate of CO(2) conversion. Our calculation further reveals that by using this strategy, the barrier heights of CO(2) hydrogenation can be reduced to ~0.12 eV or possibly even lower, providing unique opportunities to control the reaction rates by using different combinations of donor/acceptor ligands.