Adsorption and decomposition of H2S on C2N sheet with embedded manganese atom: First-principles calculations

In this study, the catalytic effect of a single Mn atom embedded C2N (g -C2N-Mn) system has been examined for H2S molecule decomposition using spin-polarized Density Functional Theory including Hubbard U (DFT + U) method. The aim is to design and develop a suitable material for sustainable Sulphur-tolerant fuel cells. Firstly, we investigate the minimum energy profile for trapping and splitting of the H2S molecule. It is shown that the g-C2N-Mn substrate will preferably capture the H2S molecule approaching the Mn site in the cavity. As the reaction progresses through four intermediate states, it is found that the splitting of the H2S molecule into SH and H subunits by g-C2N-Mn is thermodynamically favorable and proceeds spontaneously without an energy barrier and will gain energy of 1.61 eV in the process. The PDOS analyses account for the evolution of the electronic properties of some specific atoms in the system as the reaction proceeds. The electron density difference portrays the charge localizations (ionic) and depletion (covalent) between those identified atoms participating in the reaction. It is noted that weak chemisorption and electron transfer play an important role in the splitting of the H2S molecule. The study provides a detailed theoretical approach for describing the H2S splitting by the g-C2N-Mn substrate.