Room Temperature Dehydrogenation of Gaseous Methanol over Polycrystalline Gold Triggered and Traced by Oxygen K-edge X-rays - UTU Research Portal

A1 Refereed original research article in a scientific journal

Room Temperature Dehydrogenation of Gaseous Methanol over Polycrystalline Gold Triggered and Traced by Oxygen K-edge X-rays

Authors: Pietzsch, Annette; Niskanen, Johannes; Vaz da Cruz, Vinicius; Eckert, Sebastian; Fondell, Mattis; Jay, Raphael M.; Lu, Xingye; McNally, Daniel; Schmitt, Thorsten; Föhlisch, Alexander

Publisher: American Chemical Society (ACS)

Publication year: 2025

Journal: Journal of Physical Chemistry C

Journal name in source: The Journal of Physical Chemistry C

Volume: 129

Issue: 5

First page : 2453

Last page: 2459

ISSN: 1932-7447

eISSN: 1932-7455

DOI: https://doi.org/10.1021/acs.jpcc.4c06870

Web address : https://doi.org/10.1021/acs.jpcc.4c06870

Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/484442268

Abstract

The room temperature conversion of gaseous methanol to carbon monoxide and hydrogen on a polycrystalline Au film at ambient pressure has been triggered and characterized by oxygen K-edge excitation and vibrationally resolved resonant inelastic X-ray scattering. The rate-limiting first methanol dehydrogenation step is driven by ultrafast O–H dissociation and deprotonation of O K-edge excited CH₃OH. The Au surface further dehydrogenates the CH₃O⁺ photoradical created by X-rays via electron transfer from the Au surface. With vibrationally resolved resonant inelastic X-ray scattering, we trace the CO molecular potential energy surface along the C–O coordinate. The CO bond softens, and the C–O stretch frequency changes from 2250 to 2065 cm^–1 at a CO chemisorption energy of 38–58 kJ/mol. This constitutes weak chemisorption as compared to the transition metals but also stronger bonding than the physisorbed CO species on single-crystal Au surfaces. In liquid methanol, the recombination of the CH₃O⁺ photoradical created by X-rays with protons quenches this conversion.

Downloadable publication

This is an electronic reprint of the original article.
This reprint may differ from the original in pagination and typographic detail. Please cite the original version.

pietzsch-et-al-2025-room-temperature-dehydrogenation-of-gaseous-methanol-over-polycrystalline-gold-triggered-and-traced.pdf

Funding information in the publication:
We thank R. C. Couto for giving us access to the CO gas RIXSdata and L. Weinhardt for providing the methanol gas RIXSreference spectrum. A.F. acknowledges funding from the ERC-ADG-2014 - Advanced Investigator Grant No. 669531 EDAXunder the Horizon 2020 EU Framework Program for Researchand Innovation. The work at PSI was supported by the SwissNational Science Foundation (SNSF) through the NCCR(National Centre of Competence in Research) MARVEL(Materials’ Revolution: Computational Design and Discoveryof Novel Materials) and the Sinergia network “Mott PhysicsBeyond the Heisenberg Model (MPBH)” (SNSF ResearchGrants CRSII2_160765/1 and CRSII2_141962). X.L. ac-knowledges financial support from the European Community’sSeventh Framework Programme (FP7/2007-2013) underGrant agreement No. 290605 (COFUND: PSI-FELLOW).Part of this research was conducted within the HelmholtzVirtual Institute VI 419 ‘Dynamic Pathways in Multidimen-sional Landscapes’. Preparatory studies were performed usingthe EDAX@UE49-SGM beamline, the nmTransmissionNEXAFS at the UE52-SGM beamline and the chemistry labat the BESSY II synchrotron at the Helmholtz-Zentrum, Berlin.This research was performed at the SAXES instrument of theSwiss Light Source of the Paul Scherrer Institut in Villigen PSI,Switzerland.