From Tailpipes to Treasure: Recycling PGMs in Auto Catalysts

Since the 1970s, automotive exhaust catalysts have driven massive demand for platinum group metals (PGMs). In 2008, this sector consumed 118.3 tons of platinum (Pt), 136.2 tons of palladium (Pd), and 23.6 tons of rhodium (Rh). These figures represented 63.7%, 60%, and 110% of that year’s global mine output, respectively.

Between 1975 and 2008, the world used a staggering 4,119 tons of PGMs in catalytic converters—1,836.3 tons of Pt, 1,918 tons of Pd, and 365 tons of Rh. Remarkably, this total equals 10 times the 2008 mine production.

In China, PGM consumption for catalysts has surpassed 100 tons annually. However, this dwarfs the country’s domestic mine output, exceeding it by 50 to 60 times.

Industry estimates suggest that spent catalysts require replacement every 5–7 years or 50,000–70,000 km. Consequently, the global market now demands 100–200 million replacement units yearly, needing ~200 tons of recycled PGMs—about half of 2010’s mined supply.

Looking ahead, China’s replacement demand will likely reach 10–20 million units per year within 4–5 years. As a result, its annual PGM recycling volume could exceed 20 tons.

Experts often call spent automotive catalysts “mobile PGM mines.” Today, recovering metals from them fuels a booming global recycling industry. Given its economic and environmental impact, this sector has drawn intense academic interest worldwide.