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Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
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Shape-Controlled Pathways in the Hydrogen Production from Ethanol Steam Reforming over Ceria Nanoparticles
Julia Vecchietti1, Patricia Pérez-Bailac2,3, Pablo G Lustemberg2,4
1Instituto de Desarrollo Tecnológico para la Industria Química, UNL-CONICET, Güemes 3450, 3000 Santa Fe, Argentina.
ACS Catalysis
|August 29, 2022
Summary
Ethanol surface reactions differ significantly between cerium oxide nanooctahedra and nanocubes. Nanocubes, exposing more reactive facets, yield 2.4 times more hydrogen (H2) production due to distinct ethoxy species and reaction pathways.
Area of Science:
- Surface Chemistry
- Catalysis
- Materials Science
Background:
- Cerium oxide (CeO2) is a crucial material in catalysis.
- Surface structure and facet exposure significantly influence CeO2 reactivity.
- Understanding ethanol surface reactions is key for developing efficient catalytic processes.
Purpose of the Study:
- To investigate the ethanol surface reaction mechanism over CeO2 nanooctahedra (NO) and nanocubes (NC).
- To correlate the observed reaction pathways with the exposed crystallographic facets ((111) for NO, (100) for NC).
- To elucidate the role of different adsorbed ethoxy species in hydrogen (H2) production.
Main Methods:
- Temperature-Programmed Surface Reaction Infrared Spectroscopy (TPSR-IR)
- Temperature-Programmed Surface Reaction Mass Spectrometry (TPSR-MS)
- Density Functional Theory (DFT) calculations
- Electron Spin Resonance (ESR) activity measurements
Main Results:
- CeO2-NC exhibited 2.4 times higher H2 production than CeO2-NO.
- Different ethoxy species (monodentate, bidentate) were identified on (111) and (100) facets.
- The (100) facet showed an additional pathway for H2 formation via formate species.
- Enhanced H2 production was confirmed on CeO2 nanocubes via ESR.
Conclusions:
- The shape of CeO2 nanoparticles dictates the types of adsorbed ethoxy species and subsequent reaction pathways.
- The (100) facet of CeO2 is more active for H2 production from ethanol compared to the (111) facet.
- Facet-dependent reaction mechanisms explain the enhanced catalytic performance of CeO2 nanocubes.
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