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Surface intermediates steer the pathways of CO2 hydrogenation on Pt/γ-Al2O3: Importance of the metal-support interface.
- Source :
-
Journal of Catalysis . Sep2023, Vol. 425, p40-49. 10p. - Publication Year :
- 2023
-
Abstract
- [Display omitted] • Pt-H formation on the Pt surface. • Oxygen vacancy is generated at the interface. • The mobile *HCO 3 as a reservoir for CO 2 supply. • Formate is the spectator rather than the active intermediate. • Carboxylate pathway dominates the CO 2 hydrogenation. A variety of adsorbed intermediates have been extensively assigned during CO 2 hydrogenation on Pt/γ-Al 2 O 3. However, the surface sites where the surface species reside have not been well resolved, which are extremely important to depict the reaction pathways of CO 2 hydrogenation. In the current work, surface species adsorbed on three regions were distinguished by in situ diffuse-reflectance infrared Fourier transform spectroscopy, i.e., contiguous Pt region of Pt nanoparticle, interfacial Pt int -O-Al int region between Pt nanoparticle and γ-Al 2 O 3 , and surface region of γ-Al 2 O 3 away from Pt nanoparticle. The dynamics of adsorbed H species, carbonyl species, bicarbonates, formate species, and adsorbed CO 2 , were identified at different sites, proving that the reaction occurs at the Pt/γ-Al 2 O 3 interface. We found that only the C-containing species at the Pt perimeter are directly active intermediates for the reaction. Such spatial analysis bridges the gap between the hydrogen activation and CO 2 activation, providing a deep understanding of CO 2 hydrogenation. In addition, the interface structure with oxygen vacancy is important for CO 2 activation, driving the reaction through carboxylate (*HOCO) pathway to form CO at the interface rather than formate (*HCOO) pathway and then be hydrogenated at the Pt surface. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00219517
- Volume :
- 425
- Database :
- Academic Search Index
- Journal :
- Journal of Catalysis
- Publication Type :
- Academic Journal
- Accession number :
- 164859099
- Full Text :
- https://doi.org/10.1016/j.jcat.2023.05.028