Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6504586 | Catalysis Today | 2018 | 47 Pages |
Abstract
The effect of Si and Al promoted in TiO2 catalysts on both acid-base properties and 2-propanol dehydration was studied. The sol-gel method was used to prepare pure TiO2 and TiO2-Al2O3 and TiO2-SiO2 mixed oxides with 1%, 3% and 10% of Al2O3 or SiO2. The structure and surface characterization (XRD, TG-DTA, N2 sorption, 27Al and 19Si MAS NMR) revealed that the promoted cations were dispersed in the TiO2 lattice. The acid and basic sites density was measured by NH3-TPD and CO2-TPD. FTIR-pyridine-TPD revealed predominantly Lewis-type acidity for all these catalysts and a low presence Brønsted-type acidity was detect only for 10% SiO2 promoted catalyst. The change in the activity of 2-propanol decomposition was useful to detect the effect of type and content of cation in the acid-base properties of promoted catalysts. The acid-base molar ratio of the catalytic surface was increased as a function of content of Al and Si and it was related to the increase in the alcohols decomposition activity. Dehydration activity was more sensitive for the Si-promoted catalysts than the Al-promoted ones, showing an important role of cation coordination in the acidic and catalytic properties of these mixed oxides.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Catalysis
Authors
Gustavo Pérez-López, Román RamÃrez-López, Tomás Viveros,