First principle study of NH3 adsorption on Pd13 clusters supported by transition metal dichalcogenide XY2 (X=Mo, W; Y = S, Se, Te)

The adsorption of NH3 on Pd-13 clusters supported by two-dimensional, transition metal dichalcogenide XY2 (X = Mo, W; Y = S, Se, Te) has been studied using first principle, density functional theory with D3 correction. For NH3 adsorption on MoY2 (Y = S, Se, Te)-supported Pd-13 clusters, the chemisorption energy is in the order of Pd-13/MoS2 > Pd-13/MoSe2 > Pd-13/MoTe2, and the chemisorption energy is in the order of Pd-13/WS2 > Pd-13/WSe2 > Pd-13/WTe2 on WY2 (Y = S, Se, Te)-supported Pd-13 clusters. The order of adsorption strength correlates well with charge transfer and the integrated crystal orbital Hamiltonian population. Compared to pristine Pd (111) surfaces, the adsorption energies on the XY2-supported Pd-13 cluster are significantly increased by 63-92%; compared to the experimental value on Pd foil, the adsorption energies on the XY2-supported Pd-13 cluster are also significantly increased by 55-81%. Our results contribute to the understanding of the mechanism of NH3 adsorption enhancement on transition metal dichalcogenide-supported Pd clusters and to the design of high-performance Pd catalytic clusters for NH3 adsorption.