A new organic–inorganic hybrid ionic liquid polyoxometalate for biodiesel production

Abstract

A series of organic–inorganic hybrid ionic liquid polyoxometalate were synthesized by combining of 12-tungstophosphoric acid with different sulfonated organic cations. These compounds were used as catalysts in the esterification of oleic acid with methanol. Key physicochemical properties of these hybrids, including their melting points, acidities and solubilities in methanol were determined. Special attention was paid to the temperature-dependence solubilities of these hybrids as a function of their organic cations. Based on experimental findings, a new thermoregulated recoverable homogeneous catalysis system was introduced for biodiesel production. The hybrid catalyst could be reused several times without significant loss of its catalytic activity. As a preliminary application, the hybrid was used as a catalyst in biodiesel production from soybean oil and methanol. Studies reveal that our catalytic system is a promising candidate for biodiesel production from feedstock with high free fatty acids and water content.