title: A nanometric Rh overlayer on a metal foil surface as a highly efficient three-way catalyst.
abstract: Pulsed arc-plasma (AP) deposition of an Rh overlayer on an Fe-Cr-Al stainless steel foil produced a composite material that exhibited high activity for automotive three-way catalysis (TWC). The AP pulses deposited metallic Rh nanoparticles 1-3 nm in size, whose density on the surface increased with the number of pulses. This led to coalescence and grain growth on the foil surface and the eventual formation of a uniform two-dimensional Rh overlayer. Full coverage of the 51 μm-thick flat foil by a 3.2 nm-thick Rh overlayer was achieved after 1,000 pulses. A simulated TWC reaction using a miniature honeycomb fabricated using flat and corrugated foils with the Rh overlayers exhibited successful light-off at a practical gaseous hourly space velocity of 1.2 × 10(5) h(-1). The turnover frequency for the NO-CO reaction over the metallic honeycomb catalyst was ca. 80-fold greater than that achieved with a reference Rh/ZrO2-coated cordierite honeycomb prepared using a conventional wet impregnation and slurry coating procedure. Despite the nonporosity and low surface area of the foil-supported Rh overlayer compared with conventional powder catalysts (Rh/ZrO2), it is a promising alternative design for more efficient automotive catalysts that use less Rh loading.
authors.affiliation: Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Misumi
authors.affiliation: Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan.|Unit of Elements Strategy Initiative for Catalysts &Batteries, Kyoto University, Kyoto, 615-8245, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshida
authors.affiliation: Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan.|Unit of Elements Strategy Initiative for Catalysts &Batteries, Kyoto University, Kyoto, 615-8245, Japan.|Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama, 332-0012, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hinokuma
authors.affiliation: Technical Division, Faculty of Engineering, Kumamoto University, Kumamoto, 860-8555, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sato
authors.affiliation: Department of Applied Chemistry and Biochemistry, Graduate School of Science and Technology, Kumamoto University, Kumamoto, 860-8555, Japan.|Unit of Elements Strategy Initiative for Catalysts &Batteries, Kyoto University, Kyoto, 615-8245, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Machida