Synergetic Role of Thermal Catalysis and Photocatalysis in CO Reduction on Cu/MoS.

Effective activation of CO is a primarily challenging issue in CO reduction to value-added hydrocarbon chemicals, due to the large energy gap between the highest-occupied and lowest-unoccupied molecular orbitals (HOMO-LUMO). Here, we employ state-of-the-art first-principles calculations to explore the synergetic role of thermal catalysis and photocatalysis in CO reduction, on typical single-atom scale catalyst, i.e., Cu magic cluster on a semiconducting two-dimensional MoS substrate. It is identified that only about 1% of the hot electrons excited from the MoS substrate by at least 6.3 eV photons may be trapped by the inert CO molecule at the expense of 400 fs. Moreover, the physisorption-to-chemisorption transition of CO can be observed within 500 fs upon overcoming an about 0.05 eV energy barrier. Contrastingly, upon chemisorption, the activated CO species may trap about 7% of the hot electron excited from the MoS substrate by about 2.5 eV visible photons, with a cost of 140 fs.