Solar-assisted selective separation and recovery of precious group metals from deactivated air purification catalysts

Meijun Wu; Yao Chen; Zhenpeng Guo; Xinru Wang; Hanyun Zhang; Ting Zhang; Shuhui Guan; Zhenfeng Bian

doi:10.1016/j.scib.2024.04.058

Solar-assisted selective separation and recovery of precious group metals from deactivated air purification catalysts

Sci Bull (Beijing). 2024 Apr 26:S2095-9273(24)00307-4. doi: 10.1016/j.scib.2024.04.058. Online ahead of print.

Authors

Meijun Wu¹, Yao Chen², Zhenpeng Guo¹, Xinru Wang¹, Hanyun Zhang³, Ting Zhang¹, Shuhui Guan¹, Zhenfeng Bian⁴

Affiliations

¹ Ministry of Education Key Laboratory of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China.
² Ministry of Education Key Laboratory of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China; Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China.
³ Shanghai YK Pao School, Shanghai 201620, China.
⁴ Ministry of Education Key Laboratory of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China. Electronic address: bianzhenfeng@shnu.edu.cn.

PMID: 38729803
DOI: 10.1016/j.scib.2024.04.058

Abstract

The mitigation of environmental and energy crises could be advanced by reclaiming platinum group precious metals (PGMs) from decommissioned air purification catalysts. However, the complexity of catalyst composition and the high chemical inertness of PGMs significantly impede this process. Consequently, recovering PGMs from used industrial catalysts is crucial and challenging. This study delves into an environmentally friendly approach to selectively recover PGMs from commercial air purifiers using photocatalytic redox technology. Our investigation focuses on devising a comprehensive strategy for treating three-way catalysts employed in automotive exhaust treatment. By meticulously pretreating and modifying reaction conditions, we achieved noteworthy results, completely dissolving and separating rhodium (Rh), palladium (Pd), and platinum (Pt) within a 12-h time frame. Importantly, the solubility selectivity persists despite the remarkably similar physicochemical properties of Rh, Pd, and Pt. To bolster the environmental sustainability of our method, we harness sunlight as the energy source to activate the photocatalysts, facilitating the complete dissolution of precious metals under natural light irradiation. This eco-friendly recovery approach demonstrated on commercial air purifiers, exhibits promise for broader application to a diverse range of deactivated air purification catalysts, potentially enabling implementation on a large scale.

Keywords: Air purification catalysts; Photocatalysis; Platinum group precious metals; Selective recovery.