GM Recognized For Development Of The Emissions-Reducing Catalytic Converter

[Bruce Nunnally]

PONTIAC, Mich. – General Motors’ development of the first production-ready catalytic converter for automobiles will be recognized by GlobalSpec with a “Great Moments in Engineering” award at a ceremony in Detroit later this month.

GM’s breakthrough research, development and engineering led to the company’s 1975 introduction of the emissions-reducing device, which was used in conjunction with unleaded gasoline. Since then, catalytic emission control and unleaded gasoline have been used on vehicles around the world.

“The catalytic converter has made a dramatic impact on lowering the emissions output of vehicles, leading to cleaner air and paving the way for greater powertrain efficiencies in today’s cars, trucks and SUVs,” said Tom Stephens, executive vice president, GM Global Powertrain and Global Quality. “Our global GM team is diligently focused on delivering future propulsion technologies that will address the energy and environmental challenges facing the globe.”

A catalytic converter affects vehicle emissions by transforming or significantly reducing engine combustion-generated pollutants. As exhaust gases leave the engine, they pass through the converter, where a honeycomb structure coated with precious metals, palladium, platinum, and rhodium, promotes a chemical reaction that converts pollutants to less harmful emissions before they exit the car’s exhaust system.

Emissions-reducing technology began showing up on automotive engines in the late 1960s, but mandates for even cleaner-burning engines pushed the catalytic converter’s development in the early 1970s. It also hastened the phase-out of leaded gasoline, which was incompatible with the converter’s precious-metal components.

Although the concept of the catalytic converter was not invented by GM, the company is credited with the innovations that enabled the catalytic converter to work in the wide range of operating environments seen by cars and trucks, including the special materials and chamber design that made the converter more effective.

Prior to GM’s introduction of the catalytic converter, there were daunting reliability, durability and vehicle drivability challenges that prevented the introduction of catalytic converters on automobiles. GM’s pioneering work on the catalytic converter was spearheaded by a team of GM and AC Delco scientists and engineers in the early 1970s. This work led then-GM President Edward N. Cole in 1971 to announce unilaterally that all GM engines would have lower compression ratios and hardened valve seats to make them compatible with unleaded gasoline and its lower octane level. That decision prepared the automotive and oil industries for the adoption of catalytic converters and unleaded gasoline for the 1975 model year.

“GM has a distinguished history of technology leadership innovations inspired and developed by a global team of very talented engineers and scientists,” said Larry Burns, vice president of Research and Development. “We are pleased that GlobalSpec is recognizing our industry leadership in the development of the catalytic converter.”

In the nearly 35 years since its practical implementation, GM has continued to lead with advanced catalytic converter technology. Many GM vehicles now use more than one converter and include “close-coupled” converters that are mounted very close to or are incorporated with engine exhaust manifolds. This promotes quicker heat-up of the converter for lower emissions when the engine is cold, and a greater overall reduction in harmful emissions.