Nanophase-separated Ni3Nb as an automobile exhaust catalyst

Toyokazu Tanabe, Tsubasa Imai, Tomoharu Tokunaga, Shigeo Arai, Yuta Yamamoto, Shigenori Ueda, Gubbala V. Ramesh, Satoshi Nagao, Hirohito Hirata, Shin Ichi Matsumoto, Takeshi Fujita, Hideki Abe

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9 Citations (Scopus)

Abstract

Catalytic remediation of automobile exhaust has relied on precious metals (PMs) including platinum (Pt). Herein, we report that an intermetallic phase of Ni and niobium (Nb) (i.e., Ni3Nb) exhibits a significantly higher activity than that of Pt for the remediation of the most toxic gas in exhaust (i.e., nitrogen monoxide (NO)) in the presence of carbon monoxide (CO). When subjected to the exhaust-remediation atmosphere, Ni3Nb spontaneously evolves into a catalytically active nanophase-separated structure consisting of filamentous Ni networks (thickness < 10 nm) that are incorporated in a niobium oxide matrix (i.e., NbOx (x < 5/2)). The exposure of the filamentous Ni promotes NO dissociation, CO oxidation and N2 generation, and the NbOx matrix absorbs excessive nitrogen adatoms to retain the active Ni sites at the metal/oxide interface. Furthermore, the NbOx matrix immobilizes the filamentous Ni at elevated temperatures to produce long-term and stable catalytic performance over hundreds of hours.

Original languageEnglish
Pages (from-to)3374-3378
Number of pages5
JournalChemical Science
Volume8
Issue number5
DOIs
Publication statusPublished - 2017

ASJC Scopus subject areas

  • Chemistry(all)

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    Tanabe, T., Imai, T., Tokunaga, T., Arai, S., Yamamoto, Y., Ueda, S., Ramesh, G. V., Nagao, S., Hirata, H., Matsumoto, S. I., Fujita, T., & Abe, H. (2017). Nanophase-separated Ni3Nb as an automobile exhaust catalyst. Chemical Science, 8(5), 3374-3378. https://doi.org/10.1039/c6sc05473k