Synthesis of acid–base bifunctional CaO/ITQ-2 zeolite catalyst for phosphorylation of dodecanol

• An efficient, novel CaO/ITQ-2 catalyst was prepared possessing acid and alkaline sites.
• The alkalinity of zeolite has improved after modification by CaO.
• It possesses high activity for esterification reaction and high selectivity for diester.
• An acid–base cooperative manner to catalyze esterification reaction

A series of acid–base bifunctional CaO/ITQ-2 zeolite catalysts were prepared by introducing calcium into the ITQ-2 zeolite. The catalysts were characterized by X-ray diffraction, FT-IR, NH3-TPD and CO2-TPD. The characterization results proved that ITQ-2 zeolite was synthesized by delaminating the MCM-22 zeolite. After modification by CaO, the catalysts could simultaneously have alkaline and acidic sites with little structural change. We then studied the catalytic capabilities of the prepared catalysts in the phosphorylation of dodecanol to di-dodecyl phosphate (DAP). The results show that ITQ-2 catalyst has higher selectivity for DAP than MCM-22. Versus ITQ-2 zeolite, the CaO/ITQ-2 catalysts have excellent acid–base cooperativity. The conversion of phosphoric acid and the selectivity of di-dodecyl phosphate could reach 80.2% and 77.5%, respectively over 3 wt.%CaO/ITQ-2 at optimal conditions. The catalytic activity of CaO/ITQ-2 catalyst could be regenerated by roasting after four times of reusing.

The prepared CaO/ITQ-2 catalyst possesses both alkaline sites and acidic sites, and exhibited obvious acid–base complementary effect with good catalytic performance for phosphorylation of dodecanol.Figure optionsDownload as PowerPoint slide