Platinum

Platinum is more than just a symbol of prestige in the jewellery world; it is a critical industrial powerhouse. Known as one of the rarest elements in the Earth's crust, this silver-white transition metal possesses a unique combination of physical and chemical properties that make it indispensable to the global economy. From reducing vehicle emissions to fighting cancer, platinum’s utility extends far beyond its shimmering surface.

This guide explores the science, history, extraction, and diverse applications of platinum, providing a detailed look at why this "noble metal" remains one of the most valuable resources on the planet.

1.0What is Platinum? 

Platinum (chemical symbol Pt, atomic number 78) is a dense, malleable, and highly ductile metal belonging to the platinum group metals (PGMs), which also includes palladium, rhodium, ruthenium, iridium, and osmium.

• Atomic number: 78
• Atomic mass: 195.08 u
• Electronic configuration: [Xe] 4f¹⁴ 5d⁹ 6s¹

2.0Physical and Chemical Properties

Platinum’s remarkable resistance to chemical attack makes it suitable for harsh environments. Even aqua regia, a mixture of hydrochloric and nitric acid, is among the few reagents that can dissolve it.

3.0History of Platinum

While platinum is often considered a "modern" metal due to its complex refining requirements, its history dates back millennia.

Ancient Origins

Traces of platinum have been found in the gold artifacts of ancient Egypt, such as the Casket of Thebes (c. 700 BC), though it is likely the Egyptians did not distinguish it from silver. In South America, pre-Columbian civilizations near modern-day Ecuador used naturally occurring platinum alloys to create nose rings and ceremonial jewellery long before European arrival.

The "Little Silver" Misunderstanding

When Spanish conquistadors arrived in South America in the 16th century, they viewed the metal as a nuisance. They found it intermingled with gold ore and, unable to melt it, named it platina ("little silver") in a derogatory sense. It was often discarded into rivers to "ripen" into gold.

Scientific Rediscovery

It wasn't until the 18th century that European scientists, including Antonio de Ulloa and Charles Wood, began investigating the metal's properties. In 1751, Swedish scientist Theophil Scheffer categorized platinum as a precious metal. By the 19th century, advancements in refining techniques by chemists like William Hyde Wollaston allowed for the commercial production of pure platinum, sparking a "platinum age" in royal jewellery and industrial science.

4.0Mining and Production

Platinum is exceptionally rare. It is estimated that all the platinum ever mined would fit into a standard living room. This scarcity, combined with a labor-intensive extraction process, contributes to its high market value.

Where is Platinum Found?

The vast majority of the world's platinum comes from two primary sources:

1. South Africa: The Bushveld Igneous Complex supplies approximately 70-80% of the world's newly mined platinum.
2. Russia: The Norilsk-Talnakh region is the second-largest producer, where platinum is often a byproduct of nickel and copper mining.
   Smaller deposits are found in Zimbabwe, Canada, and the United States (Montana).

The Extraction Challenge

Extracting platinum is far more difficult than extracting gold.

• Extracting platinum is much harder than extracting gold. Nearly 10 tons of ore are needed for just one ounce of platinum. The ore is crushed, milled, and concentrated using froth flotation, then smelted at 1500°C. Finally, complex chemical refining (often with aqua regia) separates platinum from other metals like palladium and rhodium. The whole process can take up to six months.

5.0Platinum in Catalysis

Platinum’s most important application lies in catalysis — accelerating chemical reactions without being consumed. Its catalytic activity stems from its ability to adsorb gases such as hydrogen, oxygen, and carbon monoxide on its surface.

Heterogeneous Catalysis

Platinum acts as a heterogeneous catalyst — meaning the catalyst is in a different phase from the reactants (usually solid platinum with gaseous reactants).
For example:

• Hydrogenation of alkenes: Platinum provides active sites for hydrogen atoms to attach and react with unsaturated hydrocarbons.
• Oxidation reactions: In catalytic converters, platinum oxidizes harmful carbon monoxide (CO) into less toxic carbon dioxide (CO₂).

6.0Automotive Catalysts

Platinum plays a vital role in automobile catalytic converters, which reduce exhaust emissions. These converters contain a ceramic honeycomb structure coated with platinum (and other PGMs).

Reactions facilitated by platinum catalysts:

1. 2CO + O₂ → 2CO₂ (oxidation of carbon monoxide)
2. 2NO → N₂ + O₂ (reduction of nitrogen oxides)
3. CxHy + O₂ → CO₂ + H₂O (oxidation of hydrocarbons)

Such reactions are crucial in minimizing air pollution and improving air quality.

7.0Platinum in Fuel Cells

Another major field of platinum use is in proton-exchange membrane (PEM) fuel cells. Platinum catalysts enhance both hydrogen oxidation at the anode and oxygen reduction at the cathode, converting chemical energy into electrical energy efficiently.

However, researchers are exploring ways to reduce platinum loading in fuel cells due to its scarcity and cost, focusing on alloy catalysts like platinum–cobalt or platinum–nickel systems.

8.0Laboratory and Industrial Processes

Platinum’s inertness and high melting point make it ideal for laboratory apparatus such as crucibles and electrodes. It’s also used in:

• Nitric acid production (as a gauze catalyst for ammonia oxidation)
• Silicone manufacturing
• Petrochemical reforming — converting low-octane hydrocarbons into high-octane fuel components.

9.0Critical Industrial Applications

While jewellery accounts for a visible portion of platinum demand, the industrial sector consumes the lion's share.

1. Automotive Industry: The Catalytic Converter

The single largest use of platinum is in the automotive sector. It serves as the primary catalyst in catalytic converters for diesel and gasoline engines.

• How it works: A thin coating of platinum on a ceramic honeycomb structure triggers a chemical reaction that converts toxic gases—carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons—into less harmful carbon dioxide ($CO_2$), nitrogen ($N_2$), and water vapor ($H_2O$).
• Efficiency: Platinum is preferred over other metals because of its thermal durability; it continues to function effectively even under the intense heat of an exhaust system.

2. Medical Miracles

Platinum's biological inertness and conductivity make it a lifesaver in modern medicine.

• Chemotherapy: Platinum-based drugs, such as cisplatin, carboplatin, and oxaliplatin, are used to treat roughly 50% of all cancer patients. These compounds inhibit the division of cancer cells by binding to their DNA.
• Implants: Due to its conductivity and resistance to corrosion inside the body, platinum is the material of choice for electrodes in pacemakers, cochlear implants, and deep-brain stimulation devices used for Parkinson’s disease.

3. Chemical and Petroleum Industries

Platinum plays a behind-the-scenes role in the manufacture of everyday goods.

• Nitric Acid Production: Platinum-rhodium gauzes are used to catalyse the oxidation of ammonia to nitric acid, a key component of fertilisers and explosives.
• Silicone Manufacturing: Platinum catalysts are essential for curing silicones used in everything from aerospace seals to kitchen spatulas and medical tubing.
• Oil Refining: It is used in the "cracking" process to separate crude oil into gasoline, diesel, and jet fuel.

4. Electronics and Glass

• Hard Drives: Platinum is added to the magnetic layers of hard disk drives to increase data storage density.
• Fiberglass: The manufacturing of high-quality glass and optical fibers requires molten glass to pass through platinum-rhodium bushings. Only platinum can withstand the corrosive molten glass at 1,700°C without contaminating the final product.

10.0Environmental and Economic Significance

Because platinum enhances reaction rates while reducing harmful by-products, it plays a critical role in environmental protection technologies. Its ability to catalyze both oxidation and reduction reactions helps control industrial emissions and supports clean energy systems.

Its demand in the automotive, jewellery, and energy sectors makes it one of the most strategically important materials in modern industry.