Thermal Stability and CO Oxidation Property of Non-Equilibrium Pd-Ru Alloy Catalyst

• Published in: MATERIALS TRANSACTIONS Vol. 64; no. 10; pp. MT-MH2022010 - 2444
• Main Authors: Fukushima, Takeru, Tsukuda, Ryota, Ohhashi, Satoshi, Fujita, Nobuhisa, Kameoka, Satoshi
• Format: Journal Article
• Language: English
• Published: Sendai The Japan Institute of Metals and Materials 01-10-2023; Japan Science and Technology Agency
• Subjects: Al-Pd-Ru; Annealing; Approximants; Aqueous solutions; Carbon monoxide; Catalyst; CO oxidation; Intermetallic compound; Leaching; Nanocrystals; Non-equilibrium Pd-Ru alloy; Oxidation; Palladium; Palladium base alloys; Phase separation; Quasicrystals; Ruthenium; Solid solutions; Supersaturated solid solutions; Thermal stability
• ISSN: 1345-9678; 1347-5320
• DOI: 10.2320/matertrans.MT-MH2022010

The thermal stability and CO oxidation activity of a non-equilibrium Pd–Ru alloy obtained by leaching Al–Pd–Ru alloy (3/2 approximant, P40 phase: Al72Pd16.4Ru11.6 (at%)) with 20 wt% NaOH aqueous solution were investigated. When the Pd–Ru alloy was annealed under a He or H2 atmosphere, phase separation of the Pd–Ru alloy proceeded under H2 at 500 °C, whereas the non-equilibrium state was relatively stable under He at temperatures as high as 500 °C. In addition, the Pd–Ru alloy sample annealed under He (at 300 or 500 °C) showed substantially greater CO oxidation activity than those annealed under H2 (at 300 or 500 °C). The results suggested that there is a more suitable microstructure of Pd-Ru alloy in the nanocrystals for CO oxidation than the solid solution state or the phase-separated state.