Density functional investigation on structural, electronic and magnetic properties of ruthenium- or osmium-doped rhodium clusters and their application towards H2S gas sensing and activation

摘要

A density functional study is performed to establish the structural, electronic, magnetic and catalytic properties of ruthenium- or osmium-doped bimetallic as well as ruthenium-osmium-doped tri-metallic rhodium alloy clusters. Stability parameters like stability function, HOMO-LUMO gap and deformation electron density suggest a higher stability of Rh4Ru, Rh5Ru, Rh2Os, Rh4Os and Rh2RuOs. Rh2Ru, Rh2Os and Rh4RuOs also possess larger values of magnetic moment. Higher charge separations among atoms are noticed in tri-metallic in comparison to bimetallic alloys. HOMO and LUMO iso-surfaces as well as DOS diagrams reveal greater contribution of d-orbitals overlapping among all the atoms in the formation of alloy. These alloy clusters are observed to sense H2S gas in the presence of other abundant gases like O-2, N-2 and CO2. Alloy clusters can dissociate H2S via two steps with one intermediate and two transition states. Rh4Ru and Rh2RuOs clusters catalyse the dissociation of the S-H bond of H2S more effectively than other clusters.