&lt;em&gt;Operando &lt;/em&gt;sulfur speciation during sulfur poisoning-regeneration of Ru/SiO&lt;sub&gt;2&lt;/sub&gt; and Ru/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; using non-resonant sulfur Kα&lt;sub&gt;1,2&lt;/sub&gt; emission

Kuzmenko, Dzulija; Clark, Adam H.; Schildhauer, Tilman; Szlachetko, Jakub; Nachtegaal, Maarten

doi:10.1039/d0ra03068f

Operando sulfur speciation during sulfur poisoning-regeneration of Ru/SiO₂ and Ru/Al₂O₃ using non-resonant sulfur Kα_1,2 emission

Kuzmenko D, Clark AH, Schildhauer T, Szlachetko J & Nachtegaal M

Citation

Kuzmenko, D., Clark, A. H., Schildhauer, T., Szlachetko, J., & Nachtegaal, M. (2020). Operando sulfur speciation during sulfur poisoning-regeneration of Ru/SiO₂ and Ru/Al₂O₃ using non-resonant sulfur Kα_1,2 emission. RSC Advances, 10(27), 15853-15859. https://doi.org/10.1039/d0ra03068f

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:33149

A periodic oxidative regeneration of a sulfur-poisoned methanation catalyst is an alternative to the expensive state-of-the-art process of syngas cleaning using wet scrubbers. Here we have employed operando X-ray emission spectroscopy (XES) to study sulfur speciation on Ru/SiO₂ and Ru/Al₂O₃ during methanation in the presence of H₂S and subsequent regeneration in dilute O₂ at 360 °C. XES allowed us to obtain semi-quantitative sulfur speciation and to monitor changes in the absolute sulfur concentration. It was established that Al₂O₃, in contrast to SiO₂, forms sulfite/sulfate species by reacting with SO₂, which is released from the poisoned Ru surface upon oxidative treatment. The concentration of sulfite/sulfate species is reduced upon switching the feed to H₂/CO while no simultaneous increase in sulfide concentration is observed. For both catalysts, the regenerative treatment removes adsorbed sulfur as SO₂ only partially, which we propose is the main reason for the incomplete activity recovery of the poisoned catalyst after regeneration.