A homogeneous supported catalyst based on Zn(II) was prepared by anchoring complex [Zn(OAc)(2)(N, N'-chelate)] on silica, where N, N'-chelate is a suitably functionalised di-imine ligand. The complex was able to promote the esterification and transesterification of acidic vegetable oils at 160 degrees C within two hours. The catalyst could be also easily recovered and immediately re-cycled. (C) 2015 Elsevier Ltd. All rights reserved.