Recovering palladium and gold by peroxydisulfate-based advanced oxidation process.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38787950.
- Also identified by DOI 10.1126/sciadv.adm9311 and PMC identifier 11636751.
- Licence recorded as CC BY-NC.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Palladium (Pd) and gold (Au) are the most often used precious metals (PMs) in industrial catalysis and electronics. Green recycling of Pd and Au is crucial and difficult. Here, we report a peroxydisulfate (PDS)-based advanced oxidation process (AOPs) for selectively recovering Pd and Au from spent catalysts. The PDS/NaCl photochemical system achieves complete dissolution of Pd and Au. By introducing Fe(II), the PDS/FeCl<sub>2</sub>·4H<sub>2</sub>O solution functioned as Fenton-like system, enhancing the leaching efficiency without xenon (Xe) lamp irradiation. Electron paramagnetic resonance (EPR), <sup>18</sup>O isotope tracing experiments, and density functional theory calculations revealed that the reactive oxidation species of SO<sub>4</sub>·<sup>-</sup>, ·OH, and Fe(IV)═O were responsible for the oxidative dissolution process. Lixiviant leaching and one-step electrodeposition recovered high-purity Pd and Au. Strong acids, poisonous cyanide, and volatile organic solvents were not used during the whole recovery, which enables an efficient and sustainable precious metal recovery approach and encourage AOP technology for secondary resource recycling.