ACS Award in the Chemistry of Materials

Sponsored by DuPont

Stephen T. Wilson, 59, a senior R&D associate at UOP in Des Plaines, Ill., is being honored for his work with molecular sieves.

Wilson earned a B.S. in chemistry at Wake Forest University, Winston-Salem, N.C., in 1968 and a Ph.D. in chemistry at Harvard University in 1975. The following year, he began his career at Union Carbide. The company later entered into a joint venture with UOP, which is now part of Honeywell.

Wilson was the first to synthesize aluminophosphate-based molecular sieve materials (AlPOs), an advance that Stanley A. Gembicki, vice president and chief technology officer at UOP, describes as a "watershed event in the field of materials chemistry."

Before the development of AlPOs, "molecular sieve synthesis seemed limited to zeolites," Wilson explains. Zeolites consist of an open, three-dimensional, negatively charged framework made of AlO₄ and SiO₄ tetrahedra linked by shared oxygens and require a pH of 11 to 13 to crystallize.

The AlPO molecular sieves, on the other hand, "have a neutral framework made up of AlO₄ and PO₄ tetrahedra, and synthesis occurs within a pH range of about 3 to 10," Wilson says. Amines or quaternary ammonium cations can be used as templates to generate a broad range of AlPO structures. Magnesium, manganese, cobalt, zinc, and silica can be incorporated in the AlPO framework.

The flexibility of the AlPO system opened up new realms for the synthesis of catalysts and adsorbents in both industry and academia. Adding silica to AlPOs, for example, produced silicoaluminophosphates (SAPOs) with unique acid catalyst properties.

After one of Wilson's colleagues determined that the molecular sieve SAPO-34 could catalyze the conversion of methanol to olefins (MTO), Wilson optimized the catalyst's properties for this process. The resulting technology could reduce greenhouse gas emissions, Gembicki notes. Natural gas currently burned as waste at remote oil wells could be converted to methanol and then—using the cost-effective new MTO technique—to olefins.

Wilson, who has worked on numerous other catalysts, holds 60 patents and has published 35 journal articles. Though he would like to have published more, intellectual property protection often makes that difficult for industrial researchers, he says. "In industry, we do a lot of very good work that never makes it into print externally. Somebody else may make the same discovery five years from now and publish, and you'll think, 'I wish I could have published that data, because we already knew that.' "

Other than the restriction on publishing, Wilson has found that industrial life suits him well. He thrives on working in teams, particularly enjoying the interchange of knowledge that arises between colleagues with different fields of expertise. In addition, he says, "the projects that I've been associated with have called on me, over and over, to learn new stuff. There's enough variety that I feel like I've always been a student."

In fact, flexibility is crucial in business, Wilson believes. "In industry, you have to be willing to bend with the times and the needs of the business," he says. "The constraints on the kind of research you do are not only, 'Can it be done?', but also, 'Is it worth doing, and can we make any money doing it?' "

The award will be presented before the Division of Inorganic Chemistry.—Sophie Rovner