Insights into the mechanism and kinetics of propene oxidation and ammoxidation over bismuth molybdate catalysts derived from experiments and theory

Abstract

Robert K. Grasselli was a pioneer in the development and commercialization of catalysts for propene oxidation to acrolein and ammoxidation to acrylonitrile, products that today are produced at the level of over 10 billion pounds per year. The catalysts used for both processes are contain bismuth molybdates augmented by up to seven additional elements used to attain high activity, selectivity, and stability. The importance of propene oxidation and ammoxidation has stimulated considerable interest in understanding the mechanism and kinetics of these processes and the particular role of catalyst composition and structure in defining catalyst activity and selectivity. Virtually all of this work has been carried out using bismuth molybdates, primarily α-Bi2Mo3O12. The objective of this paper is to review the findings of experimental studies and illustrate how theoretical studies based on density functional theory provide additional insights that support deductions drawn from experiments and, more importantly, provide information that cannot be accessed experimentally.