H_3PO_4协同AlCl_3改性无序介孔羟基磷灰石催化合成双酚F

Irregular Mesoporous Hydroxyapatite Modified Synergistically With Phosphoric Acid and Aluminium Chloride for Catalytic Synthesis of Bisphenol F

用水热法合成无序介孔羟基磷灰石,再通过浸渍法将H_3PO_4、AlCl_3负载到无序介孔羟基磷灰石。采用XRD、FT-IR、N_2吸附-脱附、SEM、Pyridine-FT-IR和XPS对其进行表征。将H_3PO_4协同AlCl_3改性制备的改性无序介孔羟基磷灰石m-HAP-P/Al作为催化剂,用于催化合成双酚F,考察了不同AlCl_3负载量催化剂的催化活性以及反应时间、反应温度、催化剂量、酚/醛摩尔比对双酚F收率及其异构体分布的影响。结果表明,无序介孔羟基磷灰石表面P-OH与H_3PO_4的P-OH作用形成含有-P-O-P-O-P-的结构,其有利于AlC_l3协同改性形成Cl/Al原子比为2的四元环或六元环结构的改性机理,经H_3PO_4协同AlCl_3改性的无序介孔羟基磷灰石兼具Brnsted和Lewis酸位,在催化苯酚、甲醛羟烷基化合成双酚F反应中呈现较高活性。当以AlCl_3负载量为1.5mmol/g的m-HAP-P/Al作为催化剂,在反应时间120min、反应温度90℃、酚/醛摩尔比15、催化剂/甲醛质量比3的反应条件下,双酚F收率达89.56%。

The irregular mesoporous hydroxyapatites（m-HAP-P/A1） were first synthesized by the hydrothermal method and then were modified synergistically with phosphoric acid and aluminium chloride by the impregnation method. They were characterized by XRD, FT-IR, N2 adsorption- desorption, SEM, Pyridine-FT-IR and XPS. m-HAP-P/A1 was then used as catalyst for synthesis of bisphenol F. The effects of aluminium chloride content loaded on m-HAP-P/A1, and reaction conditions of time, temperature, catalyst content and phenol/formaldehyde molar ratio on bisphenol F yield and its isomers distribution were investigated. The results showed that the P--OH of irregular mesoporous hydroxyapatite reacted with P- OH groups of phosphoric acid to form -P-O-P-O-P- frame structure, which are beneficial for the synergistic modification of A1CI3 to form four membered and/or six membered rings with C1/A1 atom ratio 2. The irregular mesoporous hydroxyapatite modified synergistically with phosphoric acid and aluminium chlorideafford both Br6nsted acid and Lewis acid sites, and exhibited high catalytic activity in synthesis of bisphenol F. With m-HAP-P/A1 loaded aluminium chloride 1.5 mmol/g as catalyst, under the optimal reaction conditions of temperature of 90℃, phenol/formaldehyde molar ratio of 15 and catalyst/formaldehyde mass ratio of 3 and time of 120 min, the yield of bisphenol F reached 89.56%.