Synthesis of biodiesel from model acidic oil catalyzed by a novel solid acid catalyst SO42−/C/Ce4+

Camellia seed shell was carbonized to obtain carbon carrier (C), then the carrier was sulfonated and incorporated with Ce4+ to prepare a novel solid acid catalyst SO42−/C/Ce4+ by impregnation method. The structure and morphology of SO42−/C/Ce4+ was characterized by a variety of techniques. The catalytic activity of SO42−/C/Ce4+ was evaluated from the esterification reaction of model acidic oil with methanol, which was performed in a batch reactor. Results indicated that the highest conversion of model acidic oil was 95.45 wt% when the molar ratio of methanol to oleic acid was 12, reaction temperature was 66 °C and catalyst loading was 1 wt%. This catalyst also exhibited good catalytic stability. The high catalytic activity can be ascribed to the introduction of Ce4+ reduced the ratio of graphitic carbon sheet effectively, which is favorable for the formation of high density of strong Brönsted acid sites. The high stability can be ascribed to the formation of stable coordination bonds among Ce and O, S atoms, which strengthens the electron withdrawing function that was provided by the sulfonated-polycyclic aromatic hydrocarbons.