A study has been made by desorption mass spectrometry of the destruction of grafted acetyl groups on the surface of H-mordenite, H-ZSM-5, H-Y-faujasite, Al-containing aerosil and aluminosilicate compounds layered on an aerosil surface. It has been established that the thermal decomposition of acetyl groups attached through Brönsted acid sites proceeds with the formation of ketene over the same temperature range (320–360°C) for all the samples. The implications of this result for the strength of acid sites are discussed.
