Potentiality of photoelectron spectroscopy in the characterization of surface acidity: photoelectron and infrared spectroscopic comparative study of pyridine adsorption on NH4–Y zeolite activated at various temperatures

Abstract

Pyridine adsorption on NH₄–Y zeolites activated at temperatures ranging from 300 to 600°C has been followed by photoelectron spectroscopy (X.P.S.). A difference in binding energy of 2 eV is found between the N_1s level of pyridine adsorbed respectively on Lewis and Brönsted acid sites; parallel infrared measurements support the assignments. Quantitative results are discussed in relation to i.r. absorption data and show that X.P.S. has potential applications in the quantitative determination of surface acidity.