Professor Alexis T. Bell has been awarded the 2003 Robert Burwell Lectureship in Catalysis by the North American Catalysis Society. The Lectureship is sponsored by Johnson Matthey PLC’s Catalysts and Chemicals Division and is given in recognition of substantial contributions to one or more areas in the field of catalysis with emphasis on discovery and understanding of catalytic phenomena, catalytic reaction mechanisms and identification and description of catalytic sites and species. His research activities have led to more than 400 publications in the most prestigious journals in catalysis, chemistry and chemical engineering. Over many years he has applied cutting-edge spectroscopy and theory to study surfaces before and after catalytic reactions.
His nominators offered some of the following remarks. His earlier work with Professor Doros Theodorou pioneered the application of statistical mechanics and molecular dynamics for predicting the adsorption and diffusion of molecules in zeolites. This represented one of the first quantitative applications of theoretical methods to systems of direct catalytic relevance. Later his work with Professor Arup Chakraborty succeeded in using quantum mechanical calculations to determine the siting and stability of metal cations exchanged into zeolites. In the area of Fischer-Tropsch synthesis, his elegant use of in situ infrared methods, surface science techniques, and isotopic switch methods led to a mechanistic picture of “unprecedented clarity and relevance.” Rate constants for elementary steps and the identity and reactivity of specific adsorbed intermediates were measured and ultimately used to elucidate the underlying structure-function relations for chain growth as well as the operative basis for widely reported strong meta-supported interactions. His studies have led to demonstration of a novel bifunctional mechanism for methanol synthesis and leads to strong effects of Lewis acidity and basicity of ZrO2 on activity and selectivity. He has also made significant contributions in the area of zeolite catalysis by elucidating the mechanism of both the synthesis and function of these heterogeneous catalysts.
Together with Professor Clay Radke, the application of NMR methods led to the direct observation of the structure-directing role of organic and inorganic cations during synthesis and to a clear mechanistic picture of their self-assembly in complex solutions and gels. A combination of kinetic, infrared, isotopic and theoretical studies also led to a clearer mechanistic and structural picture of the nature of exchanged cations in zeolites and their involvement in forming and stabilizing reactive intermediates in the reduction of NO by hydrocarbons. In the area of metal oxides, Alex pioneered the use of Raman spectroscopy for the structural characterization of dispersed structures. His applications of these methods to the characterization of oxidative dehydrogenation catalysts led to specific assignments of site reactivity and to a comprehensive picture of the mechanism and site requirements for desired and undesired reactions of alkanes on dispersed oxides. More recently, working in collaboration with Professor Enrique Iglesia, he has also explored the use of in situ UV-visible and X‑ray absorption spectroscopy in measuring the number of active sites and reduced centers during alkane oxidation reactions. Throughout all this work, Alex has repeatedly demonstrated a natural talent that allows him to translate his research on catalytic phenomena, catalytic reaction mechanisms, and the identification and description of catalytic sites for a wide range of chemistries into understandable terms for his audience.
The lectureship comes with an honorarium and travel stipend that will allow him to visit many of the local clubs of the North American Catalysis Society in order to stimulate both young and old minds to the marvels of catalysis.
John N. Armor