Surface Species in Photocatalytic Methanol Reforming on Pt/TiO2(110): Learning from Surface Science Experiments for Catalytically Relevant Conditions

Constantin A. Walenta, Carla Courtois, Sebastian L. Kollmannsberger, Moritz Eder, Martin Tschurl, Ueli Heiz

Research output: Contribution to journalArticlepeer-review

39 Scopus citations

Abstract

Photocatalytic hydrogen evolution from methanol is a standard test reaction for photocatalyst materials. Surprisingly, the exact chemical mechanism is still widely discussed in the literature. In order to disentangle photochemical from thermal reaction steps and gain insights on the atomic level, we use a Pt cluster-loaded TiO2(110) photocatalyst in very well-defined environments. Using Auger electron spectroscopy, temperature-programmed desorption/reaction, isotopic labeling, and isothermal photoreactions, it is possible to identify the surface species present on the catalyst under photocatalytic conditions. Furthermore, an initial conditioning of the photocatalyst is observed and attributed to thermal dehydrogenation of methanol to CO species on the cluster. The analysis of the isothermal photoreactions reveals that the photo-oxidation kinetics are not significantly affected by cocatalyst loading. The observed conversion and product distribution of formaldehyde and methyl formate can be rationalized with kinetic parameters gained from the bare TiO2(110) crystal. The work leads to a detailed mechanistic understanding of the surface species and paves the way for an educated microkinetic modeling approach, which may be extended to a variety of noble metal cocatalysts and other TiO2 modifications.

Original languageEnglish
Pages (from-to)4080-4091
Number of pages12
JournalACS Catalysis
Volume10
Issue number7
DOIs
StatePublished - 3 Apr 2020
Externally publishedYes

Keywords

  • Pt cluster loaded TiO(110)
  • photocatalytic conditions
  • surface species

Fingerprint

Dive into the research topics of 'Surface Species in Photocatalytic Methanol Reforming on Pt/TiO2(110): Learning from Surface Science Experiments for Catalytically Relevant Conditions'. Together they form a unique fingerprint.

Cite this