Determining the surface acidic properties of solid catalysts by amine titration using Hammett indicators and FTIR-pyridine adsorption methods

Surface acidity of solids (ZSM-5 zeolites, Y zeolite, mordenite and Ca-bentonite) were investigated with Fourier transform infrared spectroscopy (FTIR) and Hammett acidity functions; the n-butylamine titration method. In the amine titration method, acid strength of solids were found. The total acid amount of Y zeolite has the highest value among all others. The IR spectrums of all samples were recorded using diffuse reflectance infrared Fourier transform (DRIFT) technique. Pyridine adsorption and desorption processes have given some clues about the surface acidity of solids. Copyright (C) 2010 John Wiley & Sons, Ltd.