Adsorption of SF6 decomposition components over Pd (1 1 1): A density functional theory study

This work studies the adsorption properties of Pd(1 1 1) surface to various SF₆ decomposition components (H₂S, SO₂, SOF₂, and SO₂F₂). Due to the affluent active d electronic of Pd transition metal, the density functional theory has been used to analyze the adsorption properties of Pd(1 1 1) surface to H₂S, SO₂, SOF₂, and SO₂F₂, including the adsorption structures, adsorption energy, and charge transfer. The results show that the adsorption abilities of these gases on the Pd(1 1 1) surface is in the following order: SO₂ > H₂S > SOF₂ > SO₂F₂, and all of the adsorption processes are exothermic. Besides, the density of states is further calculated to analyze the interaction mechanism during the adsorption processes. We conclude that SO₂ and H₂S interact with Pd(1 1 1) surface by physisorption. SOF₂ and SO₂F₂ tend to adsorb on Pd(1 1 1) by molecular adsorption, as the energy barriers of dissociation adsorption process is too high for the SOF₂ and SO₂F₂ molecules to cross.