Development of advanced exhaust-gas catalyst


Development of advanced exhaust-gas catalyst without precious metals and rare-earth elements

Precious metals (Pt and Pd) and rare earth elements (CeO2) are typical materials for heterogeneous exhaust-gas catalysts in automotive systems. However, their limited resources and high market-driven prices are principal issues in realizing the path toward a more sustainable society.

Herein, we have developed an earth-abundant nanoporous NiCuMnO catalyst by leaching Mn from a CuNiMn precursor. The developed catalyst was catalytically active and durable for NO reduction and CO oxidation. During catalytic reactions, the nanostructure was self-transformed into a more active nanostructure; in particular, the Cu/CuO regions derived from the nanostructure were very active, and further significant coarsening was not observed without the loss of activity, as these regions were tangled with a stable nanoporous NiMnO network (Fig.1). The self-transformed nanostructure successfully completed a long-term durability test for NO reduction at 400°C for 10 days. The in situ TEM clearly provided evidence for the instant reaction-induced self-transformation of the nanostructure. The important implication for general catalyst design has been reached.

Production of the nanoporous catalysts can be easily scaled up (Fig.2), and they may be a rational alternative to traditional precious-metal catalysts for automotive systems in the near future.

pr_160202_04.jpgFig.1 Scanning TEM image and element mapping of the developed nanoporous catalyst.

pr_160202_06.jpgFig.2 Mass production of the developed catalyst.
(Left) Appearance in bottles, 400g in total. (Right) SEM image of the gas-atomized micropowders.

Researcher Information

Research Area “New Materials Science and Element Strategy”
Research Theme “Ubiquitous element based innovative nanoporous metal composite and device”

Journal Information

“Earth-Abundant and Durable Nanoporous Catalyst for Exhaust-Gas Conversion”

DOI: 10.1002/adfm.201504811(will open in a new tab)

Contact information

For enquires about this research

Prof. Takeshi Fujita
Advanced Institute for Materials Research, Tohoku University

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Dr. Hideki Abe
Environmental Remediation Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science

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