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oai:recercat.cat:10256/137212024-06-18T13:52:49Zcom_2072_452955com_2072_2054col_2072_453073

2024-06-18T13:52:48Z urn:hdl:10256/13721 Excitonic Interfacial Proton-Coupled Electron Transfer Mechanism in the Photocatalytic Oxidation of Methanol to Formaldehyde on TiO2(110) Migani, Annapaola Blancafort San José, Lluís Fotocatàlisi Photocatalysis Funcional de densitat, Teoria del Density functionals Reacció d'oxidació-reducció Oxidation-reduction reaction Protons -- Reaccions de transferència Proton transfer reactions CH3OH on a single-crystal rutile TiO2(110) surface is a widely studied model system for heterogeneous photocatalysis. Using spin-polarized density functional theory with a hybrid functional (HSE06), we study the photocatalytic oxidation of CH3OH adsorbed at a coordinately unsaturated Ti site as an excited-state process with triplet spin multiplicity. The oxidation to CH2O is stepwise and involves a CH3O intermediate. The first O-H dissociation step follows an excitonic interfacial proton-coupled electron transfer mechanism where the hole-electron (h-e) pair generated during the excitation is bound, and the h is transferred to the adsorbate. The O-H dissociation paths associated with other h-e pairs are unreactive, and the moderate experimental efficiency is due to the different reactivity of the h-e pairs. The excited-state CH3O intermediate further deactivates through a seam of intersection between the ground and excited states. It can follow three different paths, regeneration of adsorbed CH3OH or formation of the ground-state CH3O anion or an adsorbed CH2O radical anion. The third channel corresponds to photochemical CH2O formation from CH3OH, where a single photon induces one electron oxidation and transfer of two protons. These results expand the current view on the photocatalysis of CH3OH on TiO2(110) by highlighting the role of excitons and showing that adsorbed CH3OH may also be an active species in the photocatalytic oxidation to CH2O We acknowledge financial support from Spanish Ministerio de Economía y Competitividad (FIS2012-37549-C05-02, UNGI10-4E-801, RYC-2011-09582, CTQ2015-69363-P), Generalitat de Catalunya (2014SGR-301, 2014SGR-1202, XRQTC), and computational time from BSC Red Española de Supercomputación and Consorci de Serveis Universitaris de Catalunya 2024-06-18T13:52:48Z 2024-06-18T13:52:48Z info:eu-repo/date/embargoEnd/2026-01-01 info:eu-repo/date/embargoEnd/2026-01-01 2016-12-14 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/10256/13721 info:eu-repo/semantics/altIdentifier/doi/10.1021/jacs.6b11067 info:eu-repo/semantics/altIdentifier/issn/0002-7863 info:eu-repo/semantics/altIdentifier/eissn/1520-5126 info:eu-repo/grantAgreement/MINECO//CTQ2015-69363-P/ES/OMPUTACION DEL ESTADO EXCITADO: DE ESPECTROS MOLECULARES A SISTEMAS MULTICROMOFORICOS/ Tots els drets reservats info:eu-repo/semantics/embargoedAccess American Chemical Society (ACS) © Journal of the American Chemical Society, 2016, vol. 138, núm. 49, p. 16165-16173 Articles publicats (D-Q)