William Kovarik
Radford University
and
Matthew E. Hermes
Kennesaw State University

Fuels and Society C: 2. GM's Decision for the Catalytic Converter

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But mobile source – automobiles – were also creating smog problems that were noticeable after WWII. The concerns led to the Clean Air Act of 1970 which required 90 percent reductions in auto exhaust. The mandatory reduction was controversial, and had not yet been approved by Congress, when on January 14, 1970, GM president Ed Cole told a Society of Automotive Engineers conference that the “pollution free” car was possible if two conditions were met:

• Cars used a new devices called a catalytic converter; and
• Lead was taken out of gasoline.

Catalytic converters would greatly reduce carbon monoxide, nitrogen oxides and hydrocarbons (unburned fuel).  The converters would do nothing to lower lead emissions, but their use made leaded gasoline impossible since lead would deactivate the main catalytic element, platinum. Unleaded gasoline would be necessary.

There was an irony in Cole’s speech that was widely acknowledged at the time. After all, the company that had created leaded gasoline was now announcing its demise. Aware that this moment might come, GM had pulled out of the leaded gasoline business only a few years before, in 1962, when it sold its interests in Ethyl Corp. to a small paper company in Richmond, Va.

GM’s proactive position on lead and catalytic converters should be seen in the context of the many pressures on the auto industry in the 1960s and 70s. Biting critiques by consumer advocates like Ralph Nader, anti-trust lawsuits by the federal government, Congressional investigations and a growing environmental movement all combined to convince GM that the time had come for change.

Catalytic converters were not introduced to reduce lead, as is sometimes suggested. It was the drive to reduce nitrogen oxides and CO that forced the converter – and ended TEL in U.S. gasoline. Even if there had been no public health issue with lead, the converters would still have needed unleaded gasoline. But new public health research did indicate serious problems and this was used as an added justification for eliminating leaded gasoline.

In 1973, Ethyl Corp. sued the EPA and won a temporary victory when a federal court set aside the leaded gasoline phase-out regulations, saying EPA hadn’t demonstrated that lead was a public health hazard. This ruling was overturned in favor of the EPA in 1976 when a federal appeals court said while lead was not a certain danger, “awaiting certainty will often allow for only reactive not preventive regulation.”

Catalytic converters are now a standard part of a car’s exhaust system. They reduce three main types of emissions: hydrocarbons HC (unburned fuel); carbon monoxide CO; and nitrogen oxides NOx. The converter reduces the nitrogen oxides back to nitrogen and oxygen and oxidizes carbon monoxide and hydrocarbon emissions.

You review catalytic converter chemistry next, or go on to the lead phase-out, that accompanied and was triggered by the introduction of the catalytic converter.