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Homolytic H2 dissociation for enhanced hydrogenation catalysis on oxides.
- Source :
- Nature Communications; 1/15/2024, Vol. 15 Issue 1, p1-11, 11p
- Publication Year :
- 2024
-
Abstract
- The limited surface coverage and activity of active hydrides on oxide surfaces pose challenges for efficient hydrogenation reactions. Herein, we quantitatively distinguish the long-puzzling homolytic dissociation of hydrogen from the heterolytic pathway on Ga<subscript>2</subscript>O<subscript>3</subscript>, that is useful for enhancing hydrogenation ability of oxides. By combining transient kinetic analysis with infrared and mass spectroscopies, we identify the catalytic role of coordinatively unsaturated Ga<superscript>3+</superscript> in homolytic H<subscript>2</subscript> dissociation, which is formed in-situ during the initial heterolytic dissociation. This site facilitates easy hydrogen dissociation at low temperatures, resulting in a high hydride coverage on Ga<subscript>2</subscript>O<subscript>3</subscript> (H/surface Ga<superscript>3+</superscript> ratio of 1.6 and H/OH ratio of 5.6). The effectiveness of homolytic dissociation is governed by the Ga-Ga distance, which is strongly influenced by the initial coordination of Ga<superscript>3+</superscript>. Consequently, by tuning the coordination of active Ga<superscript>3+</superscript> species as well as the coverage and activity of hydrides, we achieve enhanced hydrogenation of CO<subscript>2</subscript> to CO, methanol or light olefins by 4-6 times. Zhu et al. report a quantitative and time-resolved analysis of hydrogen activation on Ga<subscript>2</subscript>O<subscript>3</subscript>, specifically shedding light on the long-standing puzzle of homolytic dissociation as opposed to the heterolytic pathway on oxides. [ABSTRACT FROM AUTHOR]
- Subjects :
- HYDROGEN analysis
MASS spectrometry
OXIDES
CATALYSIS
TRANSIENT analysis
Subjects
Details
- Language :
- English
- ISSN :
- 20411723
- Volume :
- 15
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Nature Communications
- Publication Type :
- Academic Journal
- Accession number :
- 174799464
- Full Text :
- https://doi.org/10.1038/s41467-024-44711-7