CHARACTERIZATION BY SIMS OF BRONSTED ACID CHEMISORPTION ON MGO(100) AND CS MGO(100)/

The room temperature chemisorption of a variety of molecules possessin g Bronsted acid character has been investigated on MgO(100) and Cs/MgO (100) substrates by secondary ion mass spectrometry (SIMS). The adsorb ates studied include: acetylene (ethyne), hydrogen sulphide, 2-propano l, acetone (2-propanone), formic acid and methanol. The emphasis of th e study is placed on the qualitative identification of the adsorbed sp ecies which is in most cases the conjugate base of the Bronsted acid. An exception is 2-propanol whose interaction with MgO and Cs/MgO appar ently involved dehydration. There is also evidence for decomposition o f formic acid in its initial interaction with Cs/MgO.