John H. Sinfelt | Unleaded-gas leader, 80

John H. Sinfelt, 80, a chemical engineer whose research for an oil company helped lead to the introduction of unleaded gasoline and significant reductions in air pollution, died May 28 in Morristown, N.J. The cause was complications of congestive heart failure.

In the late 1960s and 1970s, the petroleum industry was under pressure to produce gas without lead, which contributed to air pollution and posed health risks. Lead was added to gasoline to raise octane levels, which helped keep engines from knocking. In 1973, the Environmental Protection Agency issued regulations calling for a gradual reduction in the lead content of gas.

Mr. Sinfelt was working for the Standard Oil Development Co. (now Exxon Mobil Research & Engineering), where he specialized in developing techniques to speed up chemical reactions. While the entire industry was pursuing the goal, said Stuart Soled, a research associate at Exxon Mobil, it was Mr. Sinfelt who came up with a catalytic process using a combination of two metals, platinum and iridium, allowing refiners to inexpensively produce high-octane gasoline without adding lead.

He patented that method, and his ideas became important in further research into chemical reactions, said Enrique Iglesia, who worked with Mr. Sinfelt and who is now a professor of chemical engineering at the University of California, Berkeley.

For Mr. Sinfelt's breakthrough, President Jimmy Carter presented him with the President's National Medal of Science in 1980. The citation recognized his work "leading to the development of new catalyst systems for the production of low-lead gasoline."

Mr. Sinfelt was born in Munson, Pa., north of Altoona, and graduated from Pennsylvania State University. He completed his master's and Ph.D. in chemical engineering at the University of Illinois.

- N.Y. Times News Service