Photocatalytic Deacon Reaction over SrTiO3

Rath, T. and Deitermann, M. and Zhao, G. and Wilma Busser, G. and Jansen, H. and Schwiderowski, P. and Xia, W. and Muhler, M.

Volume: 5 Pages: 521-525
DOI: 10.1002/cptc.202000314
Published: 2021

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 H2O 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. © 2021 The Authors. ChemPhotoChem published by Wiley-VCH GmbH

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