Reassessment of Recycling Rates of Platinum Group Metals (PGMs) and Their Impact on Sustainability Models.

A reliable estimate of the impact of recycling is crucial for a fact-based assessment of the current and future sustainability of platinum group metal (PGM)-based catalysts. Recycling rates in the literature are usually calculated based on published market data, notably from Johnson Matthey, but as these reported data exclude "closed-loop" recycling, this method leads to a significant underestimation of recycling volumes. Harnessing Johnson Matthey's primary PGM market research and its proprietary suite of supply/demand/recycling models, we publish here an estimate of closed-loop recycling volumes. We find that closed-loop recycling volumes are much larger than open-loop recycling (which is reported in market data as secondary PGM supply) and that it is likely that between 50 and 60% of the metal used on new products is now sourced from recycling (globally on average). The significant reduction in global warming potential (GWP) of recycled (secondary) PGMs compared to newly mined (primary) metal means that an estimate of the proportion of recycled metal in a catalytic process or PGM-based product must be properly factored into LCA models. Our data and scenarios suggest that the GWP impact of PGMs can be reduced by 1 order of magnitude when a recycling "closed loop" is put in place within a process, underscoring the sustainability benefit of implementing routine recycling wherever practicable and ensuring that the recovered metal is retained.