Efficient synthesis of biodiesel over well-dispersed sulfated mesoporous SiO2 colloidal spheres

An effective method in obtaining tailored mesoporous SiO2 colloidal spheres of which exhibit a specific surface area of 1204 m2 g− 1 and pore volume of 0.86 cm3 g− 1 with pore size of 2.85 nm. It allows an easy control over the morphology, size and dispersity of the hybrid spheres by the variation of synthetic conditions. The formation mechanism of as-prepared mesoporous spheres was further proposed. Treated with sulfuric acid, the resulted SiO2 colloidal spheres exhibited excellent catalytic activity in the synthesis of biodiesel via the esterification of long-chain free fatty acids.234