Assembling of 12-Tungstophosphoric Acid into Amino-Modified SBA-15 and its Catalytic Performance

Abstract

12-tungstophosphoric acid was supported on amine-modified SBA-15 by impregnation. The structure and properties of the catalyst were characterized by FT-IR spectroscopy, X-ray diffraction, N2 adsorption-desorption, TEM,Raman spectra and NH3–TPD technology.the result confirmed the mesostructure for SBA-15 and the Keggin structure of the heteropolyanions was preserved. The tungstophosphoric acid can disperse in the pore of the support SBA-15/NH2, but the acidity of the catalyst reduced. The catalytic activities of the catalysts were evaluated for the esterification reaction of ethyl acetoacetate and ethylene glycol .and the catalysts supported on amine-modified SBA-15 show excellent reusability and selectivity.

Water-tolerant heteropolyacid on magnetic nanoparticles as efficient catalysts for esterification of free fatty acid

“…There are several methods for the synthesis of stable materials for leaching of HPAs in polar media, such as encapsulation of HPAs in a solid matrix and application of a support modified with functional groups such as carboxylic groups, lactam, amide, imide or amino groups for the anchoring of POMs. [12][13][14][15][16][17][18][19][20] Amino-modified silica materials are widely used for the immobilization of POMs. In spite of the decrease of acidity after chemically anchoring HPAs to the amino-modified support, these HPA/NH 2 -support systems can be used as catalyst for different acid-type reactions, showing easy handling and water-tolerant properties.…”