Platinum Group Metals in Catalytic Conveters

The platinum group metals (PGMs) are key components in today’s catalytic converter technology. Almost all cars are equipped with catalytic converters which reduce vehicles’ emissions of dangerous exhaust pollutants.

An automotive catalytic converter is one of the several elements of an exhaust system that reduces the emission of harmful pollutants, such as carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx). The catalytic function of the converter will activate certain oxidation and/or reduction reactions, which transform these harmful pollutants into carbon dioxide (CO2), water (H2O) and nitrogen (N2).

A converter typically consists of one or more honeycomb bricks coated with a "slurry" containing PGMs (Platinum Group Metals). The substrate is protected from vibration and shock by a mineral or metallic 'mat' and then packaged into a stainless steel can.

Automotive catalyst material consists of a ceramic or metallic substrate coated by an aluminium oxide-based wash coat. This wash coat contains a combination of platinum group metals (Pt, Pd, Rh for automotive; Pt, Pd for Diesel) which provide for the catalytic function.

More than 96 percent of cars manufactured today are equipped with catalysts. According to the International Organization of Motor Vehicle Manufacturers, global automobile production is at 60 million automobiles per year with this number expected to rise.

As more stringent emissions legislation continues to be introduced, catalytic converters and diesel particulate filters will become increasingly important for emissions control in the transportation industry, and on other off-road hydrocarbon-burning engines (lawnmowers, chainsaws, etc.).
By 2009, all passenger vehicles, not just "cars," are to be 99 % less polluting than vehicles sold in the 1960s.

Similar restrictions are being adopted in Europe and Japan. Other parts of the world also are implementing automotive emissions control programs that require the use of automotive catalysts.