Comparison of homogeneous and heterogeneous catalysts in dye-sensitised photoelectrochemical cells for alcohol oxidation coupled to dihydrogen formation.

Autor: Bruggeman DF; Homogeneous, Supramolecular and Bio-Inspired Catalysis, van 't Hoff Institute for Molecular Sciences, University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands j.n.h.reek@uva.nl., Mathew S; Homogeneous, Supramolecular and Bio-Inspired Catalysis, van 't Hoff Institute for Molecular Sciences, University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands j.n.h.reek@uva.nl., Detz RJ; Netherlands Organisation for Applied Scientific Research (TNO) - Energy Transition Studies Radarweg 60 Amsterdam The Netherlands., Reek JNH; Homogeneous, Supramolecular and Bio-Inspired Catalysis, van 't Hoff Institute for Molecular Sciences, University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands j.n.h.reek@uva.nl.
Jazyk: angličtina
Zdroj: Sustainable energy & fuels [Sustain Energy Fuels] 2021 Sep 30; Vol. 5 (22), pp. 5707-5716. Date of Electronic Publication: 2021 Sep 30 (Print Publication: 2021).
DOI: 10.1039/d1se01275d
Abstrakt: This study examines two strategies-homo- and heterogeneous approaches for the light-driven oxidation of benzyl alcohol in dye-sensitised photoelectrochemical cells (DSPECs). The DSPEC consists of a mesoporous anatase TiO 2 film on FTO (fluorine-doped tin oxide), sensitised with the thienopyrroledione-based dye AP11 as the photoanode and an FTO-Pt cathode combined with a redox-mediating catalyst. The homogeneous catalyst approach entails the addition of the soluble 2,2,6,6-tetramethylpiperidine-1-oxyl ( TEMPO ) to the DSPEC anolyte, while the heterogeneous strategy employs immobilisation of a TEMPO analogue with a silatrane anchor ( S-TEMPO ) onto the photoanode. Irradiation of the photoanode oxidises the TEMPO -moiety to TEMPO+ , both in the homogeneous and the heterogeneous system, which is a chemical oxidant for benzyl alcohol oxidation. Photoanodes containing the heterogeneous S-TEMPO+ demonstrate decreased photocurrent, attributed to introducing alternative pathways for electron recombination. Moreover, the immobilised S-TEMPO demonstrates an insufficient ability to mediate electron transfer from the organic substrate to the photooxidised dye, resulting in device instability. In contrast, the homogeneous approach with TEMPO as a redox-mediating catalyst in the anolyte is efficient in the light-driven oxidation of benzyl alcohol to benzaldehyde over 32 hours, promoted by the efficient electron mediation of TEMPO between AP11 and the organic substrate. Our work demonstrates that operational limitations in DSPECs can be solved by rational device design using diffusion-mediated electron transfer steps.
Competing Interests: There are no conflicts to declare.
(This journal is © The Royal Society of Chemistry.)
Databáze: MEDLINE
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