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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
Preferential CO oxidation in hydrogen: reactivity of core-shell nanoparticles
Anand Udaykumar Nilekar1, Selim Alayoglu, Bryan Eichhorn
1Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Journal of the American Chemical Society
|May 13, 2010
Summary
We designed novel core-shell nanoparticle (NP) catalysts with improved activity for preferential CO oxidation (PROX) in hydrogen. Ru@Pt core-shell NPs showed the highest performance, demonstrating efficient CO oxidation at low temperatures.
Area of Science:
- Materials Science
- Catalysis
- Nanotechnology
Background:
- Developing efficient catalysts for preferential CO oxidation (PROX) in hydrogen is crucial for fuel cell applications.
- Core-shell nanoparticles offer tunable catalytic properties by controlling interfacial effects.
Purpose of the Study:
- To design, synthesize, and characterize novel M@Pt core-shell nanoparticle (NP) catalysts.
- To investigate their catalytic performance for PROX reactions.
- To elucidate the fundamental mechanisms governing their reactivity using Density Functional Theory (DFT).
Main Methods:
- First-principles guided design and synthesis of M@Pt core-shell NPs (M = Ru, Rh, Ir, Pd, Au).
- Characterization using X-ray diffraction, FTIR, HRTEM, and temperature-programmed reaction.
- Evaluation of catalytic activity and selectivity for PROX.
- Mechanistic studies using DFT calculations.
Main Results:
- Synthesized M@Pt core-shell NPs with controlled Pt shell thickness (~1-2 monolayers).
- Observed significantly improved PROX activity and selectivity for several M@Pt NPs compared to monometallic and bimetallic nanoalloys.
- Ru@Pt core-shell NPs demonstrated the highest activity, achieving complete CO oxidation by 30°C.
- DFT studies revealed that enhanced activity stems from available CO-free Pt sites for O2 activation and a distinct hydrogen-mediated CO oxidation pathway.
Conclusions:
- M@Pt core-shell NPs represent a promising strategy for designing highly active and selective PROX catalysts with reduced platinum content.
- The core metal significantly influences the catalytic performance of the Pt shell.
- Understanding the reaction mechanism provides insights for future catalyst development.
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