Introduction of Magnetic Core-Shell Hydrogenation Catalysts for CBDO|CAS:3010-96-6| Synthesis

CBDO is an important raw material for polyester synthesis. CBDO is mainly used to prepare copolyester materials and improve the performance of traditional polyesters. So far, the mature synthesis method in the world is to collect and polymerize DMK after ANIB or AIB cracking into TMCD, and then hydrogenate to obtain CBDO. TMCB hydrogenation reaction mostly adopts slurry bed hydrogenation reactor, but the separation of catalyst particles and reaction solution is difficult. In view of the above problems, CN112023939A provides a magnetic core-shell hydrogenation catalyst, the catalyst is represented as Fe3O4@S/M, and the specific preparation steps of the catalyst are as follows:

1.Preparation of Fe₃O₄ nanoparticles

Under nitrogen protection, the iron-containing precursor compound was dissolved in ethylene glycol to obtain a transparent iron-containing solution. sodium acetate, polyethylene glycol and sodium citrate were added and heated to 100-200℃, and stirred for 1-3 h. Crystallize the uniformly mixed solution at 100-200℃ for 8-16h. wash the crystallized black solution with ethanol, and vacuum dry at 60-80℃ for 10-20h to obtain Fe₃O₄ nanoparticles.

2.Preparation of Fe₃O₄@S

The Fe₃O₄ nanoparticles were placed in a dilute hydrochloric acid solution for 10-60 minutes, and the surface was treated with acid, and the Fe₃O₄ nanoparticles were magnetically separated and washed with ethanol. The Fe₃O₄ nanoparticles are re-dispersed in the mixed solution of alcohol water or alcohol-acetonitrile, and stirred for 1-3 hours with the aid of ultrasound. ammonia water is slowly added to adjust the pH to 9-12. Dissolving the shell carrier or/and its precursor compound in a mixed solution of anhydrous ethanol and anhydrous acetonitrile. Slowly inject the obtained solution into the mixed solution containing Fe₃O₄, and stir for 1-3h at 30-80℃ with the aid of ultrasound. The resulting mixture is crystallized at 100-200℃ for 10-20 h. The crystallized black solution was washed with ethanol, magnetically separated, and vacuum-dried at 60-80℃ for 10-20 h to obtain Fe₃O₄@S;

3.Preparation of Fe₃O₄@S/M

Dissolve the precursor compound containing the active metal or/and the promoter in an anhydrous alcohol solvent, and stir to a transparent homogeneous solution. Disperse Fe₃O₄@S in a homogeneous solution under ultrasonic-assisted stirring. Add the alkaline solution, adjust the pH to 10-12, and continue to ultrasonic-assisted stirring for 10-20h. Magnetically separate the solid, wash with absolute ethanol, and vacuum dry at 60-80℃ for 10-20 h. The obtained powder is calcined at 200-300℃ for 2-6 h in an air atmosphere, and the heating rate is 2-5℃/min to obtain Fe₃O₄@S/M.

The above catalysts have the following advantages: fast hydrogenation rate for TMCB, high conversion rate of raw materials, high selectivity to target products, and strong magnetic properties, which can achieve rapid magnetic separation without filtration separation.

References

CN112023939A Magnetic core-shell hydrogenation catalyst and method for preparing CBDO.