Platinum and palladium are platinum group metals (PGM), a classification which also includes iridium, osmium, rhodium and ruthenium. Both metals are highly valued for their rarity, durability and wide-ranging applications, which makes them particularly important in the automotive industry, jewellery making and clean energy. Today, the importance of these metals to global markets is growing, especially amidst the transition to a green economy. Despite belonging to the same group of metals, platinum and palladium differ markedly in their properties and applications.
What is palladium?
Palladium is a silvery-white metal, known for its cubic crystal lattice structure. First discovered in 1802 by William Hyde Wollaston, today it is mined primarily in Russia (92 tonnes per year) and South Africa (71 tonnes per year) – the two undisputed leaders in palladium production. Palladium is one of the world’s rarest metals, and is approximately 15 to 30 times scarcer than gold, which accounts for its high price. Palladium is lightweight, durable and highly corrosion-resistant, making it suitable for use in harsh environments.
What is platinum?
Platinum, discovered in the 18th century, is another platinum group metal and has some similarities to palladium. Platinum is heavier, denser and has a higher melting point, making it suitable for high-temperature applications. The main production centres for platinum are in South Africa and Russia. South Africa is the leading producer, holding about 95% of the world's platinum reserves.
Key physical differences
Though platinum and palladium may appear similar, there are some significant differences in their physical properties:
- Density and melting point: Platinum has a density of 21.45 g/cm³, compared with 12.0 g/cm³ for palladium, meaning that platinum is denser and heavier. Platinum's higher melting point makes it suitable for more intensive applications.
- Hardness: Palladium is slightly more durable than platinum, making it more scratch-resistant. However, platinum is more malleable, which makes it popular in the crafting of intricate jewellery. Unlike platinum, palladium does not require rhodium plating to maintain its shine.
Applications in jewellery and catalytic converters for vehicles
- Jewellery: Both metals are used in the jewellery industry for their resistance to corrosion and their attractive colour. Palladium is usually used to create alloys such as white gold, whereas platinum is often used in high-end jewellery because of its weight and hypoallergenic properties.
- Automotive industry: The primary use for palladium is in the automotive industry, where it serves as a key component in catalytic converters for petrol-powered vehicles. Between 2 and 7 grams of palladium is used in each converter to convert harmful emissions into less toxic substances, which is especially important in the context of tightening environmental standards. Platinum is also used in catalytic converters, but more often for diesel vehicles. Vehicle manufacturers often switch between platinum and palladium depending on price fluctuations in order to minimise production costs.
Industrial applications and green energy
- Hydrogen energy: Both metals are playing a role in the development of hydrogen energy. Palladium's ability to absorb up to 900 times its own volume of hydrogen makes it an ideal material for storing and purifying hydrogen. Platinum is a key component of fuel cells, acting as a catalyst for converting hydrogen and oxygen into water and electricity.
- Water purification and solar power: Palladium is also used in cutting-edge water purification technologies, particularly in the creation of efficient and environmentally friendly disinfection systems. Recent research also points to the use of palladium in solar energy, particularly as a new material for photovoltaic panels. This technology is in its early experimental stages, but is expected to significantly boost efficiency when converting luminous energy into electrical energy.
- Electronics: Platinum and palladium also have a wide range of applications in electronics. Palladium is used in ceramic capacitors in laptops and mobile phones, and platinum is used in hard drives, optical fibres and thermocouples.
- Medicine: Platinum plays an important role in medicine, especially in chemotherapy. It is also an important element in pharmaceuticals, with platinum compounds used to treat various cancers.
Price trends and economic viability
Both metals have experienced significant price volatility in recent years. Palladium prices rose sharply between 2020 and 2022, reaching $3,000 per troy ounce as a result of supply shortages driven by tightening environmental standards in the automotive industry. Despite a subsequent fall in prices (palladium is trading at $1,200 per troy ounce at the time of writing, while platinum is trading at $1,027), palladium remains more expensive than platinum due to its higher scarcity and the demand for catalytic converters.
Platinum, on the other hand, has had a more stable price trajectory, with moderate growth thanks to increasing demand for industrial applications and the development of the hydrogen economy. Analysts forecast a slow but steady increase in platinum prices, while palladium prices are likely to decline due to the growing popularity of electric vehicles, which do not require catalytic converters.
Global production and resource concentration
Russia and South Africa dominate production for both metals. South Africa holds about 95% of the world’s platinum reserves, while Russia leads palladium production, producing about 92 tonnes per year. This level of concentration poses a potential supply disruption risk.
Environmental impact and future prospects
- Environmental factors: Both metals have an important role to play in a sustainable future. Palladium is used in catalytic converters, which help to reduce harmful emissions from cars. Platinum, in turn, is indispensable in fuel cells, making it an important component in the development of green energy.
- The future of EVs: As electric vehicles become more popular, demand for catalytic converters and therefore palladium and platinum may decline. However, new applications in hydrogen energy and fuel cells give cause for optimism in terms of the continued importance of these metals.
- Solar power and new research: Researchers are continuing to explore the use of palladium in solar panels in order to make energy conversion more efficient. Work is also underway to improve palladium membranes for hydrogen energy, which could significantly improve their service life and efficiency.
Conclusion
Platinum and palladium are critical metals, each with unique properties that make them suitable for a wide variety of applications. Thanks to its weight, high melting point and strength, platinum is ideal for high-temperature industrial applications and jewellery. Palladium, which is light, resistant to corrosion and highly durable, is an essential metal for the automotive industry, hydrogen storage and advanced technologies in areas such as solar panels. Both metals continue to find new applications, notably in green energy.
