Infrared Investigation of H2S Adsorption and Decomposition on Alumina and on Alumina Supported Molybdenum Sulfide

Adsorption and subsequent reaction of H 2 S on alumina gave major i.r. bands at 1341, 1568, 1625, and 3400 cm −1 . Relative band intensities were used to follow the first order decomposition of adsorbed H 2 S and formation of H 2 O. Rate constants of the surface reaction at 23, 55, and 80 °C were 0.70, 1.48, and 3.42 × 10 −3 s −1 , respectively. A mechanism consistent with the observed spectral and kinetic data involved adsorption to an exposed Al ion forming an AlS surface bond, and hydrogen bonding to neighboring O and OH species. It was assumed that the sulfur remained on the surface as a sulfide. The 1568 cm −1 band was discussed in terms of an AlO species.With adsorption on MoS 2 -Al 2 O 3 , bands appeared at 1330 and 1575 cm −1 . Behavior in all respects was similar to that observed on the alumina support alone.