Influence of H2S on ZrO2-based gasification gas clean-up catalysts: MeOH temperature-programmed reaction study

• Published in: Applied catalysis. B, Environmental Environmental, 2012-01, Vol.111-112, p.605-613
• Main Authors: Kauppi, E. Inkeri, Rönkkönen, E. Hanne, Airaksinen, Sanna M.K., Rasmussen, Søren B., Bañares, Miguel A., Krause, A. Outi I.
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Effect of H2S; Exact sciences and technology; General and physical chemistry; MeOH adsorption; MeOH-DRIFTS; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Zirconia catalyst
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2011.11.013

[Display omitted] ► ZrO2-based catalysts are active in tar removal during gasification gas clean-up. ► The effect of H2S on catalyst activity differs for ZrO2 and Y2O3-ZrO2in comparison with SiO2-ZrO2. ► Study by characterization methods using MeOH and H2S probes. ► Adsorption sites for H2S differed for the three studied catalysts. ► Effect of H2Son the activity during gas clean-up was correlated with the reactions of H2S on the surfaces. Addition of H2S in the gasification gas stream has been found to improve naphthalene and ammonia conversion over ZrO2 and Y2O3-ZrO2 catalysts, whereas over SiO2-ZrO2 such effect has not been observed. The differences in the properties of the catalysts were studied by spectroscopic (MeOH-DRIFTS) and temperature-programmed methods (H2S-TPD and MeOH-TPSR). Methanol was also used to probe the changes after sulfidation of the catalysts. H2S adsorption sites were found to be different on the ZrO2 and Y2O3-ZrO2 catalysts compared with the ones on the SiO2-ZrO2 catalyst. Sulfur was also found to be more reactive on the ZrO2 and Y2O3-ZrO2 catalysts than on SiO2-ZrO2. It was suggested, that the positive effect of H2S on naphthalene conversion during gasification gas clean-up is connected with the reactions of adsorbed sulfur on their surface. In contrast, on SiO2-ZrO2 the lack of such an effect may be related to limited reactivity of sulfur on the surface.