Recovery of Pd as PdO from Pd/SiO2 catalyst by leaching using hydrochloric acid

Ye Eun Kim, Mi Yeon Byun, Kwan Young Lee, Man Sig Lee

Research output: Contribution to journalArticlepeer-review


The recovery of Pd from spent catalysts has been gaining attention due to its high economic value and limited availability in nature. To recover and reuse Pd, leaching in HCl–H2O2 media and recovery of Pd from the Pd/SiO2 catalyst were investigated. The Pd/SiO2 catalyst was leached using 3 M HCl solution with different concentrations of H2O2; then 0.5 M NaOH was added to precipitate the Pd ions. The leaching parameters were as follows: temperature, time, H2O2 concentration, and pulp density. A 100% leaching efficiency of Pd was obtained through the addition of 5 vol% H2O2 in 3 M HCl at pulp density of 50 g/L at 80 °C for 120 min. Complete recovery of Pd was obtained at a pH = 9 due to the hydrolysis of Pd. These results indicate that the leaching time and presence of H2O2 played a key role in the stable formation of aqueous Pd–Cl complexes and in improving the mass transfer efficiency. The palladium powder obtained was palladium oxide, and the purity of palladium oxide was 86.6%. Consequently, it is expected that the obtained PdO powder can be utilized in glass, ceramic, and catalyst applications.

Original languageEnglish
Pages (from-to)1657-1664
Number of pages8
JournalJournal of Material Cycles and Waste Management
Issue number4
Publication statusPublished - 2021 Jul

Bibliographical note

Funding Information:
This work was financially supported by Ulsan Metropolitan City (IZ-20-0540), Korea Institute of Industrial Technology (KITECH) through the Research and Development (KITECH EH-21-0006) and (KITECH EO-21-0001).

Publisher Copyright:
© 2021, Springer Japan KK, part of Springer Nature.


  • Hydrometallurgy
  • Leaching
  • Palladium
  • Pd/SiO catalyst
  • Recovery
  • Recycle

ASJC Scopus subject areas

  • Waste Management and Disposal
  • Mechanics of Materials


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