Regensburg 2025 – scientific programme

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O: Fachverband Oberflächenphysik

O 32: Heterogeneous Catalysis I

O 32.9: Talk

Tuesday, March 18, 2025, 12:30–12:45, H25

Role of Co-Catalyst Loading in the Photoreforming of Tertiary Alcohols at Ambient Pressure on Titania P25 — •Paula Neumann, Clara Aletsee, Martin Tschurl, and Ueli Heiz — Chair of Physical Chemistry, School of Natural Sciences & Catalysis Research Center, Technische Universität München, Lichtenbergstr. 4, 85748 Garching, Germany

Efficient semiconductor photocatalysts are usually modified with a so-called co-catalyst, a metal particle which is commonly assumed to promote charge separation, but whose exact role remains elusive. To elucidate the influence of platinum particles loaded onto a titania powder catalyst we investigated the photoconversion of tertiary alcohols in our gas phase-photoreactor at ambient conditions. Different to its usual interpretation but in accordance with UHV studies we show that the co-catalyst facilitates the recombination of surface hydrogen. Thereby, a second reaction pathway is opened up where a C-C coupling product forms on the titania surface. Hence, identifying the mechanistics of alcohol photochemistry is not only providing insights into hydrogen formation but it also sheds light onto complex alkyl coupling reactions.

Keywords: heterogeneous photocatalysis; semiconductor; metal co-catalyst; microreactor; C-C coupling