Insights into the dominant factors of porous gold for CO oxidation

Satoshi Kameoka, Toyokazu Tanabe, Kanji Miyamoto, An Pang Tsai

    Research output: Contribution to journalArticlepeer-review

    13 Citations (Scopus)

    Abstract

    Three different porous Au catalysts that exhibit high catalytic activity for CO oxidation were prepared by the leaching of Al from an intermetallic compound, Al2Au, with 10 wt. %-NaOH, HNO3, or HCl aqueous solutions. The catalysts were investigated using Brunauer-Emmett-Teller measurements, synchrotron X-ray powder diffraction, hard X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy (TEM). Broad diffraction peaks generated during the leaching process correlated with high activity for all the porous Au catalysts. CO oxidation catalyzed by porous Au leached with NaOH and HNO3 is considered to be dominated by different mechanisms at low (< 320 K) and high (> 370 K) temperatures. Activity in the low-temperature region is mainly attributed to the perimeter interface between residual Al species (AlOx) and porous Au, whereas activity in the high-temperature region results from a high density of lattice defects such as twins and dislocations, which were evident from diffraction peak broadening and were observed with high-resolution TEM in the porous Au leached with NaOH. It is proposed that atoms located at lattice defects on the surfaces of porous Au are the active sites for catalytic reactions.

    Original languageEnglish
    Article number034703
    JournalJournal of Chemical Physics
    Volume144
    Issue number3
    DOIs
    Publication statusPublished - 2016 Jan 21

    ASJC Scopus subject areas

    • Physics and Astronomy(all)
    • Physical and Theoretical Chemistry

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