Bi-β分子筛合成条件的研究

Study on synthesis conditions for Bi-β zeolites

以四乙基氢氧化铵为模板剂、偏铝酸钠为铝源、硅胶粉为硅源、硝酸铋为铋源,在碱性条件下,水热法合成了Bi-β分子筛,该分子筛在苯乙烯氧化制苯甲醛的反应中有较好的催化活性。通过改变硅源和晶化时间,调节模板剂、偏铝酸钠和硝酸铋的用量,寻找到较佳的合成条件:n(SiO2)∶n(Al2O3)=30,n(SiO2)∶n(Bi2O3)=100,n(TEA+)∶n(SiO2)=0.5,晶化温度145℃,晶化时间3天,对合成条件的影响因素进行了探讨。

Bi-β zeolite was synthesized by hydrothermal method under alkaline condition, using SiO2 as the silica source, NaAlO2 as the aluminum source,Bi（NO3）3· 5H2O as the metal source and tetraethy- lammonium hydroxide TEAOH（28 % ） as the template. Oxidation of styrene with hydrogen peroxide to benzaldehyde was investigated over the Bi-β zeolite. It was found that crystallation time and quantity of NaAlO2, template and Bi （NO3）3· 5H2O were influencing factors for synthesis of Bi-β zeolite. The optimum condition was as follows： n （SiO2） ： n （Al2O3） = 30, n （SiO2） ： n （Bi2O3） = 100, n （TEA^＋ ） ： n （SiO2） = 0.5, crystallization temperature 145℃, crystallization time 3 d.