| 초록 |
Design of solid acid catalysts is one of the key technologies to meet the necessary challenges of economical and environmental concerns.In this context, novel and simple acid activated bentonite clay catalyst have been prepared under mild reaction conditions. The alteration product after acid activation issystematically characterized by various physico-chemical techniques such as, XRD, FT-IR, BET, and XRF analysis.Activation performed with intentof high clay concentration and mild synthetic conditions resulted in high surface area (300m2g-1), high surface acidity (30 mg KOH g-1)and high yield of product (80 %). The catalytic active sites are examined by volumetric titration, as well confirmed by pyridine adsorbed FT-IR, and advanced NH3-TPD analysis techniques.The promoted clay catalyst exhibited a promising catalytic performance for the acetalization of aldehydes/ketones with ethylene glycol/methanol, through acetals/ketals formationat room temperature (25-28 ºC) and solvent free conditions.The outstanding performance of clay catalyst is experientialin terms of high (85-90 %)conversion of carbonyl compounds and 100 % selectivity of respective acetals and ketals.The catalyst can be easily recycled up to 10 or more than 10 cycles after separation from the reaction system without considerable loss in catalytic activity. The investigated clay catalyst represent a novel class of heterogeneous catalysts useful for protection of carbonyl group in an eco-friendly manner. |
