Catalytic Deactivation of HY Zeolites in the Dehydration of Glycerol to Acrolein

Catalysts

JoséL. Contreras¹  Ricardo López-Medina¹  Sofía Hernández-Ramírez¹  Jennipher Pérez-Cabrera¹  AndrésA. Fragoso-Montes de Oca²  Juan Navarrete-Bolaños²  José Salmones³  Beatriz Zeifert³  Israel Pala-Rosas³ 

[1] Departamento de Energía, CBI, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, Col. Reynosa, 02200 Mexico City, Mexico;Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas No. 152, Col. San Bartolo Atepehuacan, 07730 Mexico City, Mexico;Instituto Politécnico Nacional, Departamento de Ingeniería Química Industrial, 07738 Mexico City, Mexico;

关键词: zeolite deactivation;    glycerol dehydration;    acrolein;    HY zeolite;    zeolite acidity;    micro/mesoporous zeolites;   

DOI  :  10.3390/catal11030360

来源: DOAJ

【 摘 要 】

The study of the deactivation of HY zeolites in the dehydration reaction of glycerol to acrolein has represented a challenge for the design of new catalysts. HY zeolites with SiO₂/Al₂O₃ molar ratios between 3.5 and 80 were studied. The solids were characterized by XRD, N₂ physisorption, SEM-EDXS, Raman and UV-vis spectroscopies, infrared spectroscopy of pyridine (FTIR-Py) and catalytic activity tests from 250 °C to 325 °C. It was found that the total amount of acid sites per unit area of catalyst decreased as the SiO₂/Al₂O₃ molar ratio increased from 3.5 to 80, resulting in the decrease in the initial glycerol conversion. The initial acrolein selectivity was promoted with the increase of the Brønsted/Lewis acid sites ratio at any reaction temperature. The deactivation tests showed that the catalyst lifetime depended on the pore structure, improving with the presence of large surface areas as evidenced by the deactivation rate constants. The characterization of the deactivated catalysts by XRD, N₂ physisorption and thermogravimetric analysis indicated that the deposition of coke resulted in the total obstruction of micropores and the partial blockage of mesopores. Moreover, the presence of large mesopores and surface areas allowed the amount of coke deposited at the catalyst surface to be reduced.

【 授权许可】

Unknown