New Insight toward Synergetic Effect for Platinum Recovery Coupling with Fe(III)-Oxalate Complexes Degradation through Photocatalysis

Platinum (Pt) is a nonrenewable mineral with limitedreserves anda patchy distribution. Pt demand and consumption are growing yearafter year. As a result, recovering Pt from the secondary resourcesis critical. A new strategy for effective Pt recovery employing Fe(III)-oxalatecomplexes under UV and visible light irradiation is proposed in thispaper. This approach can recover 98.9% of Pt in 30 min under the conditionsof 365 nm UV irradiation, leaching time = 30 min, C2O4 (2-) concentration = 333.33 g/L, and H2O2 addition = 0.60 vol %. More importantly, 95.6%of Pt can also be recovered in 8 h under sunlight. The homogeneousphotocatalytic reaction is rapid and efficient, and meanwhile, nostrong acid, base, or volatile toxic organic solvent is required.Additionally, the iron utilized in the process may be well-recycled,solving the problem of recovery difficulty of homogeneous photocatalystsand lowering the cost of leaching. Simultaneously, the Pt complexrecovered from the waste catalyst is utilized in situ to manufacture 0.1 wt % Pt/ZSM-5 catalyst, which shows the completeconversion of toluene at 200 & DEG;C and can remain stable duringthe long duration reaction of 1200 min. Overall, it can not only providea new environmentally friendly technique to recycle Pt from spentcatalysts but also save manufacturing cost of new catalysts. Extraction of platinum from waste catalystsby photocatalyticusing Fe(III)-oxalate complex solvent is discussed.