| Autor: |
Saravanan, K., Tyagi, Beena, Bajaj, Hari |
| Zdroj: |
Journal of Porous Materials; Aug2016, Vol. 23 Issue 4, p937-946, 10p |
| Abstrakt: |
Aerogel sulfated ZrO-SiO mixed oxide solid acid catalyst was prepared by sol-gel method followed by supercritical drying (SCD) in n-propanol solvent, which resulted into higher surface area (170 m/g), pore volume (0.31 cm/g) and pore diameter (7.2 nm) having ordered mesoporous structure as well as more number of Brönsted and Lewis acid sites available on larger surface area. The catalyst exhibited 91 % yield of methyl stearate at 60 °C in 7 h, which increased from 71 to 91 % with an increase in the Zr to Si ratio from 1:2 to 2:1 due to increase in acid site concentration. The reaction followed pseudo-first order kinetics under the optimized reaction conditions with a reaction rate of 1.15 mmol h, rate constant of 2.7 × 10 h and turn over frequency of 9.68 h. The catalyst displayed higher activity (91 %) compared to ion exchange resins (44-68 %), Nafion (58 %), acid clay (61 %) and pure sulfated zirconia (78 %), and was slightly lower as compared to HSO (97 %). The study clearly reveals the improved structural, textural and acidic properties of ZrO-SiO mixed oxide aerogel prepared via SCD technique. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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