CALVIN H. BARTHOLOMEW, Professor of Chemical Engineering and Head of the Catalysis Laboratory at Brigham Young University, is author or coauthor of more than 140 papers/reviews and four books and has consulted with more than fifty companies on issues relating to catalysis, air pollution, and combustion. Active in several scientific societies, he was the 1990 recipient of the Utah ACS Award, president of the California Catalysis Society, a cofounder of the Western States Catalysis Club, and a recipient of the Pope Professorship in Chemical Engineering at BYU (1995-2000).ROBERT J. FARRAUTO, Research Fellow with Engelhard Corporation, is involved in all aspects of catalysis for the environmental, chemical, and petroleum industries. Dr. Farrauto is the author of seventy papers and recipient of fifty U.S. patents and served as North and South American editor of Applied Catalysis B: Environmental from 1995-2002. He is the recipient of the International Precious Metal Institute Henry Albert Award for excellence in precious metal catalysis (2000) and the Canadian Catalysis Society Award for excellence in catalysis (1999). He is currently an adjunct professor at Columbia University, New York City, in the Department of Earth and Environmental Engineering.