Photocatalytic Deacon Reaction over SrTiO3. Issue 6 (31st March 2021)

• Record Type: Journal Article
• Authors: Rath, Tobias; Deitermann, Michel; Zhao, Guixia; Wilma Busser, G.; Jansen, Henning; Schwiderowski, Philipp; Xia, Wei; Muhler, Martin
• Is Part Of: ChemPhotoChem. Volume 5:Issue 6(2021)
• Page Start: 521
• Page End: 525
• Publication Date: 2021-03-31
• Subjects: chlorine evolution -- Deacon reaction -- hydrogen chloride oxidation -- photocatalysis -- strontium titanate; Photochemistry -- Periodicals; Periodicals; Electronic journals; 541.35
• DOI: 10.1002/cptc.202000314
• Languages: English
• ISSNs: 2367-0932

Abstract

Abstract: SrTiO3 was prepared by a polymeric precursor method and applied in the photocatalytic aerobic oxidation of HCl in a flat‐plate reactor equipped with a UV LED array (368 nm). Reaction rates up to 240 mmol h −1 m −2 and apparent quantum yields up to 33 % using an illuminated area of 60 cm −2 were achieved with highly crystalline SrTiO3 calcined at 750 °C, outperforming commercially available SrTiO3 by a factor of almost 2. A gradual catalyst deactivation was observed, which was due to the formation of crystalline SrCl2 ×2 H2 O on the surface confirmed by X‐ray diffraction, electron microscopy and X‐ray photoelectron spectroscopy (XPS). Increasing the HCl partial pressure accelerated both Cl2 formation and catalyst deactivation. XP spectra revealed an intrinsic surface segregation of Sr and the presence of several Sr‐ or O‐containing surface species. High Cl2 yields up to 42 % obtained with an illuminated area of 120 cm −2 encourage further research on a photocatalytic Deacon process for improved HCl recycling. Abstract : HCl recycling : Strontium titanate (SrTiO3 ) is identified as a highly active photocatalyst for the Deacon reaction using ultra‐violet light. Cl2 yields of up to 42 % are obtained with highly crystalline SrTiO3 calcined at 750 °C, rendering HCl recycling by aerobic photocatalysis a promising alternative to thermal and electrochemical oxidation.