Selective Oxidation of Propylene

Abstract

Publisher Summary This chapter focuses on a single aspect of selective hydrocarbon oxidation, the selective oxidation of propylene to acrolein, with the questions in mind, such as “How is propylene activated? What is the nature of the reactive oxygen species?” The selective oxidation of propylene is an important model reaction for studying oxidation reactions over oxide catalysts. Much information has been gathered over the past three decades that helps to answer these questions. Considerable evidence exists that indicates the selective oxidation of propylene proceeds via the formation of a symmetrical ally species. Subsequent steps may vary as a function of the catalyst. Some catalyst systems may abstract a second hydrogen atom before the insertion of oxygen. Others may add molecular oxygen, forming a hydroperoxide intermediate, which may then subsequently decompose into acrolein and water. While a number of oxygen species can exist on the surface of oxides, the reactive oxygen for the selective oxidation of propylene is lattice oxygen. Under reaction conditions, solid-state reactions occur that are a function of the temperature and the composition of the reacting gas mixture.