Platinum-group metals: Demand, supply, applications and their recycling from spent automotive catalysts

Abstract

The global demand for platinum-group metals (PGMs), including Pt, Pd, and Rh, far exceeds the supply of natural resources. The scarce and inhomogeneous distribution of the resources, high production costs, and serious environmental risks stimulate the recycling of PGMs from spent automotive catalysts (SAC). From this point, the global current and future accessibility and sustainability of PGMs were first evaluated by analyzing their demand, supply, applications, and recycling both globally and in several large PGMs-consuming regions. It is predicted that 195–307 t or 52–478 t of PGMs can be recovered from SAC annually according to the consumption of PGMs in automotive catalysts or the recoverable PGMs amount in the new sales/registrations of vehicles, respectively. Based on the above analysis, the reasons for the insufficient recovery of PGMs were discussed and roughly classified into the recovery technology and social factors, including the differences in the recovery initiative and progress in different regions, changeable ownership, untimely tracking of PGMs, and the absence of responsible parties for PGMs throughout the product lifecycle. It was followed by proposing the establishment and improvement of a supply-management-recycling (SMR) chain for the explication of ownership of PGMs in the service life of the product, with the intensification of the links between producers, users, and recyclers of PGMs, the increase of their recovery, and the minimization of their loss during the mining-use-deactivation-recycling processes. Finally, some suggestions were provided to reduce the dependence of catalysts on PGMs to balance the contradiction between production and consumption, pursuing the sustainable utilization of PGMs.