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Efficient recovery of platinum group metals (PGMs) from industrial spent catalysts through electrochemical means using mild conditions is of significant importance from both the industrial and the environmental points of view. Owing to their large surface-to-volume ratio, fast dissolution of PGM nanoparticles is possible through potential cycling between oxidizing and reducing potentials, leading to formation and dissolution of surface-oxide layer (transient dissolution). However, at reducing potentials, reduction of the dissolved metal species on the source nanoparticles leads to enhance the Ostwald ripening process and hence to decrease the overall dissolution efficiency significantly. We report a new concept to accelerate dissolution of Pt nanoparticles by use of surface switching species (SSS), e.g. Cu ions, functioning to selectively block the Pt surface to inhibit redeposition induced particle growth at reducing condition and expose the Pt surface to facilitate dissolution at oxidation condition, respectively. The presence of SSS during potential cycling enhances Pt dissolution by a factor of 2 or more as compared to that without SSS. Such surface self-relegation property to depress unwanted process and assist desired reaction documents an alternative and efficient approach for precious metal electrochemical recovery in dilute acidic baths with/without complexing agents.
Original languageEnglish
Article number134662
JournalElectrochimica Acta
Volume321
Number of pages11
ISSN0013-4686
DOIs
Publication statusPublished - 2019
CitationsWeb of Science® Times Cited: No match on DOI

    Research areas

  • Platinum dissolution, Recycling, Nanoparticle, Ostwald ripening, Inhibition

ID: 190878791