Journal article
Additive-Free Reductive Cleavage of Lignin Model Compounds by Ethanol-Sensitized Titania under Visible Light: A Sustainable Approach to β-O-4 Bond Cleavage
ACS sustainable chemistry & engineering, Vol.13(45), pp.19482-19495
11/17/2025
DOI: 10.1021/acssuschemeng.5c03068
Appears in UI Libraries Support Open Access
Abstract
The selective cleavage of the β-O-4 bond in lignin model compounds is a crucial step in realizing the full potential of transforming lignin to value-added aromatic compounds. Herein, we report an additive-free, visible-light-driven ligand-to-metal charge transfer (LMCT)-mediated strategy for the reductive cleavage of β-O-4 lignin model ketones in ethanol, utilizing TiO2 as the photocatalyst. We found that ethanol can act as a sensitizer and forms an LMCT complex on the surface of titania, which enables the reductive cleavage of the β-O-4 ketone under blue light (440 nm). The LMCT-sensitized titania showed moderate conversion (58%) for the reductive cleavage of β-O-4 ketone. Additionally, we observed that nitrogen doping of titania further enhances the visible light absorption and improves the conversion of the β-O-4 ketone up to 91%. EPR studies indicate the in situ generation of Ti3+ under blue light irradiation, which likely enables the reductive cleavage of β-O-4 ketone. Our work demonstrates a promising potential for the reductive cleavage of β-O-4 lignin model ketone to form value-added aromatic compounds under mild conditions without the use of an additional reductant by using ethanol (reaction solvent).
Details
- Title: Subtitle
- Additive-Free Reductive Cleavage of Lignin Model Compounds by Ethanol-Sensitized Titania under Visible Light: A Sustainable Approach to β-O-4 Bond Cleavage
- Creators
- Ayesha Khan - University of Iowa, ChemistryLogan W. Evans - University of IowaDavid B. C. Martin - University of Iowa
- Resource Type
- Journal article
- Publication Details
- ACS sustainable chemistry & engineering, Vol.13(45), pp.19482-19495
- DOI
- 10.1021/acssuschemeng.5c03068
- ISSN
- 2168-0485
- eISSN
- 2168-0485
- Publisher
- American Chemical Society
- Grant note
- Division of Chemistry: CHE-1952860 University of Iowa: NA
This work was supported by funding from the NSF (CHE-1952860) and start-up funds from the University of Iowa (UI). We acknowledge the UI Materials Analysis, Testing, and Fabrication (MATFab) facility for use of the nitrogen physisorption analysis, TGA, and XRD analysis and thank Dr. Michael Sinnwell and Dr. Daniel Unruh for their support with data collection and analysis. We also thank Mr. Brett Wagner from Carver College of Medicine and Mr. Vic Parcell from the UI High Resolution Mass Spectrometry Facility for their assistance in EPR analysis and GC-MS analysis, respectively. We acknowledge the help of Mr. Jianqiang Shao from the UI Central Microscopy Research Facility in acquiring TEM images. We thank Ms. Theodora Leventis from UI for providing us with the ethanosolv lignin sample. We also thank Mr. Raja Bale from the UMKC Missouri Institute for Defense & Energy Material Characterization Lab and Dr. Dapeng Jing from Iowa State University for XPS analysis. NMR instrumentation for this research was supported by funding from the NIH (S10-RR025500), NSF (CHE-2017828), and University of Iowa. Mass spectrometry instrumentation for this research was supported by funding from the NSF (CHE-1919422) and University of Iowa.
- Language
- English
- Electronic publication date
- 11/06/2025
- Date published
- 11/17/2025
- Academic Unit
- Iowa Neuroscience Institute; Chemistry
- Record Identifier
- 9985027360302771
Metrics
3 Record Views