Ru–Pt Core–Shell Nanoparticles for Preferential Oxidation of Carbon Monoxide in Hydrogen

Journal Article · Tue Apr 01 04:00:00 EDT 2008 · Nature Materials, 7(4):333-338

DOI:https://doi.org/10.1038/nmat2156· OSTI ID:959159

Alayoglu, Selim; Nilekar, Anand U; Mavrikakis, Manos; Eichhorn, Bryan W

The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Most of the world’s hydrogen supply is currently obtained by reforming hydrocarbons. ‘Reformate’ hydrogen contains significant quantities of CO that poison current hydrogen fuel-cell devices. Catalysts are needed to remove CO from hydrogen through selective oxidation. Here, we report first-principles-guided synthesis of a nanoparticle catalyst comprising a Ru core covered with an approximately 1–2-monolayer-thick shell of Pt atoms. The distinct catalytic properties of these well-characterized core–shell nanoparticles were demonstrated for preferential CO oxidation in hydrogen feeds and subsequent hydrogen light-off. For H₂ streams containing 1,000 p.p.m. CO, H₂ light-off is complete by 30°C, which is significantly better than for traditional PtRu nano-alloys (85°C), monometallic mixtures of nanoparticles (93°C) and pure Pt particles (170°C). Density functional theory studies suggest that the enhanced catalytic activity for the core–shell nanoparticle originates from a combination of an increased availability of CO-free Pt surface sites on the Ru@Pt nanoparticles and a hydrogen-mediated low-temperature CO oxidation process that is clearly distinct from the traditional bifunctional CO oxidation mechanism.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 959159
• Journal Information: Nature Materials, 7(4):333-338, Journal Name: Nature Materials, 7(4):333-338 Vol. 7
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
30 DIRECT ENERGY CONVERSION
ATOMS
AVAILABILITY
CARBON MONOXIDE
CATALYSTS
Environmental Molecular Sciences Laboratory
FUNCTIONALS
HYDROCARBONS
HYDROGEN
HYDROGEN FUEL CELLS
MIXTURES
OXIDATION
SYNTHESIS