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Catalytic Converters Reduce Pollution With Precious Metals

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For the average consumer, precious metals are most notably associated with jewelry, silverware and high-end consumer products. While these pieces serve important roles in culture and fashion, precious metals also serve functional roles in our everyday lives.

Precious metals, specifically platinum group metals, are key components in products that have helped advance the automotive, medical, glass and solar industries. Platinum, palladium and rhodium are resistant to corrosion and high temperatures, and have exceptional catalytic and electrical properties. It is for these reasons that the metals have served an essential role in reducing pollution caused by harmful automobile emissions.

What is a Catalytic Converter?

Today, the automotive industry utilizes precious metals to combat exhaust emissions in internal combustion engines. Catalytic converters, containing a catalyst in the form of platinum, palladium or rhodium, are used to convert the chemicals released from the exhaust of the engine into other, safer substances.

While catalytic converters are most commonly found in automobile exhaust systems, they are also used in airplanes, buses, forklifts, trucks and other types of equipment running on engines.

Legislation to Reduce Harmful Auto Emissions

Since 1975, the U.S. Environmental Protection Agency (EPA) regulations pertaining to automobile exhaust, including legislation known as the Clean Air Act, have been the driving force behind improving the process for reducing pollution emitted by automobiles.

The Clean Air Act includes multiple pieces of legislation that define the regulations upheld by the EPA for protecting and improving the nation's air quality, and the stratospheric ozone layer. As a result, the automotive industry in the United States launched the first widespread production of catalytic converters, which, according to the EPA, is the most important pollution control device on a vehicle.

Precious Metals in Catalytic Converters

Catalytic converters have three main components — the catalytic core, washcoat and the catalyst. The core is typically made of a ceramic, coned structure, but can also be made of metallic foil, and provides the catalyst with a supporting surface area. The washcoat also assists the catalyst by providing a means for distributing the materials over the core.

A typical gas engine in a vehicle produces three main pollutants — carbon monoxide, unburned hydrocarbons and oxides of nitrogen. During the catalytic process, the catalyst converts the pollutants into carbon dioxide, nitrogen and water, which are then emitted by the vehicle.  
Catalytic conversion occurs in two stages:

1. Reduction – Platinum and rhodium to help reduce the amount of nitrogen oxides, or NOx emissions. During this stage, the catalyst separates the nitrogen molecule from the atom, freeing the oxygen in the form of O2.

2. Oxidation – Unburned hydrocarbons and carbon monoxide are reduced by oxidizing, or burning, them over a platinum or palladium catalyst.

While platinum is the most active precious metal catalyst, it is also the most expensive and not ideal for all applications. It can also be used in both of stages of the catalytic conversion to reduce harmful emissions.

Recycling Catalytic Converters

Demand for palladium and platinum in the automotive industry continues to thrive, pushing the prices of these metals up, and signifying the need to recycle more than ever before. Recycling catalytic converters is a key opportunity for members of the automotive industry to profit from the precious metal content of old converters, while helping to put refined precious metals back into the market for reuse.

Because the precious metal scrap value of catalytic converters is limited, selling catalytic converters as a consumer is not a feasible transaction for the buyer or seller. Refineries will require a minimum quantity of catalytic converters per sale, making companies with large quantities of catalytic converters the ideal fit for selling.

Interested in learning more about recycling catalytic converters? Contact us today to learn about how Metallix processes precious metal contents for industrial precious metal scrap.

 
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