Probing the surface of nanosheet H-ZSM-5 with FTIR spectroscopy

Herein we report FTIR in-situ adsorption of molecular hydrogen, carbon monoxide, water, methanol, pyridine and 2,4,6-trimethylpyridine (collidine) on nanosheet H-ZSM-5 recently made and studied in the methanol to hydrocarbons reaction (MTH). The nature of the hydroxyl groups and surfaces species are described in detail. The IR spectrum of Nanosheet H-ZSM-5 is dominating by silanols, saturating the external surfaces. Acidity of Si(OH)Al is comparable to that observed in case of standard microcrystalline H-ZSM-5. The relevance of the external surface, allows to recognize Si(OH)Al species located at channel entrance and terminal Al-OH species, all accessible to hindered molecules, such as collidine.