Abstract
The acid–base properties of supported gallium oxide catalysts have been investigated by microcalorimetry and FTIR spectroscopy of pyridine (acidity) and CO 2 (basicity) adsorption. Pyridine adsorption microcalorimetry has shown that loading supports such as γ-Al 2O 3, TiO 2, and ZrO 2 with gallium oxide in a surface concentration close to the theoretical monolayer, resulted in a decrease of the surface acidity of the catalysts compared to that of the supports, while, in the case of SiO 2, new Lewis acid sites were created. The number of acid sites for the supported and bulk gallium oxide catalysts was in the following order: Ga 2O 3/SiO 2<Ga 2O 3/ZrO 2<Ga 2O 3/TiO 2≈Ga 2O 3<Ga 2O 3/Al 2O 3. This order is related to the degree of dispersion of gallium oxide on the surface of each support and to the interaction between guest and host oxides. Two types of Lewis acid sites were identified by pyridine adsorption, corresponding to the support and the supported gallium oxide, respectively. The catalysts displayed very weak basicity, except for the samples supported on zirconia and alumina.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
