Protonation of Aromatic Molecules on the Surface of Cracking Catalysts

Abstract

AbstractA series of methyl‐substituted benzene compounds and condensed nuclear hydrocarbon compounds have been studied on activated cracking catalyst surfaces using reflectance spectroscopic techniques. It was found that very intensely colored samples were obtained by activation with Brönsted acids. This coloration is attributed primarily to the formation of protonated aromatic molecule ions on the surface. The nature of these ions is discussed, and evidence is presented to support the hypothesis that protonation is involved. Some implications of these observations with regard to the mechanism of catalysis are also mentioned.