Effects of surface heterogeneity of cobalt oxyhydroxide/graphite oxide composites on reactive adsorption of hydrogen sulfide

Abstract

A high surface area cobalt oxyhydroxide and its composites with graphite oxide (GO) were prepared by a fast and simple procedure consisting of a precipitation followed by an oxidation with a strong oxidizer. The materials were tested as H2S reactive adsorbents at ambient conditions. Their structural properties and surface chemistry, before and after H2S exposure, were investigated using nitrogen adsorption, X-ray diffraction, infrared spectroscopy and thermal analysis. Results showed that the cobalt oxyhydroxide is a good H2S adsorbent. Even though the incorporation of a graphene-based phase slightly decreases the performance of cobalt oxyhydroxide, its presence promotes the retention of H2S oxidation product, SO2, on the surface. The reactive adsorption of H2S results in the formation of at least three different sulfur species underlying the complexity of the surface reactions. The detection of sulfates indicates that the oxidation is the main mechanism of H2S retention on the surface of these materials.