The recovery of platinum group metalsPlatinum Group Metals (PGM) (PGMs) from spent catalystsSpent catalyst is crucial for maintaining a sustainableSustainable PGM supplySupply. However, achieving this in an efficient and environmentally friendly manner is challenging due to the chemically stable of PGMs, which makes them resistant to dissolution in acids, and their low concentration on scrap materials. In this paper, we introduce a novel approach for PGM recovery that involves a treatment of spent catalysts with FeCl2 vapor at relatively low temperatures (< 1200 K). During this treatment, alloyingAlloying of PGMs proceeds via the disproportionation of FeCl2 vapor, resulting in the formation of ferromagnetic Fe-PGM alloys. Experimental confirmation of this phenomenon was achieved by subjecting Pt, Pd, and Rh wires to FeCl2 vapor treatment. In fundamental tests using samples simulating automobile catalysts, PGMs were successfully concentrated through magnetic separation following vapor treatment. Moreover, leachingLeaching tests using aqua regia on pulverized automobile catalysts demonstrated enhanced PGM extraction, particularly for Rh, after vapor treatmentVapor-based treatment. Thus, a process involving FeCl2 vapor treatment, magnetic separation, and acid leaching is a viable and useful method for recovering PGMsPlatinum Group Metals (PGM) from spent catalystsSpent catalyst.