Direct Recycle Palladium from Spent Automotive Catalyst to Carbon-Supported Palladium

• Published in: Journal of the Electrochemical Society Vol. 169; no. 6; pp. 63520 - 63529
• Main Authors: Wei, Jucai, Wang, Luyang, Peng, Tao, Huang, Ye, Wu, Xu
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.06.2022
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1945-7111/ac790c

In this research, a simple and economical process based on hydrometallurgy is developed to directly recycle platinum group metals from spent automotive catalysts to synthesize carbon supported platinum-group metals catalysts. Spent automotive catalysts are firstly leached by HCl+H 2 O 2 system, resulting in Pd chloro-complexes. The optimized leaching rates of Pd and Rh are 97.99 ± 2.64% and 87.70 ± 1.23%, respectively. Then Pd precursor is separated from the leaching solution by precipitation, which can remove most impurities. The Pd precursor or Pd chloro-complexes solution can be used to synthesize carbon supported catalysts directly via an ethylene glycol reduction method. The samples are characterized by SEM, TEM, XRD, EDS, and ICP-OES. 2–4 nm Pd/C are successfully synthesized using recycled Pd. The recycled Pd/C exhibits excellent long-term stability, with no activity loss in the homemade SO 3 2 c depolarized electrolyser after 150 h of 100 mA cm −2 electrolysis. The electrochemical tests indicate that the recycled Pd/C samples are not inferior to Pd/C prepared from (NH 4 ) 2 PdCl 4 reagent.