Pd/SAPO-34催化合成2-甲基-4-氨基-5-氨基甲基嘧啶

Synthesis of 2-methyl-4-amino-5-aminomethylpyrimidine by the Pd/SAPO-34 catalyst

采用水热法合成SAPO-34分子筛,并确定了合成SAPO-34分子筛的最佳晶化时间,晶化温度和初始凝胶比,通过扫描电子显微镜和X射线衍射对分子筛进行表征,确定得到形貌较好、结晶度较高的SAPO-34分子筛。以SAPO-34分子筛为载体采用浸渍法制备Pd/SAPO-34复合催化剂,通过透射电子显微镜、紫外-可见漫反射光谱、X射线光电子能谱和X射线衍射光谱对Pd/SAPO-34复合催化剂进行表征,确定SAPO-34分子筛负载金属钯后形貌依然规则完整,并且分散度较好,催化活性中心为Pd^(0)。将Pd/SAPO-34复合催化剂应用于催化合成维生素B_(1)中间体2-甲基-4-氨基-5-氨基甲基嘧啶反应,结果证明Pd/SAPO-34复合催化剂具有良好的催化效果,能使反应的转化率和选择性达到99%以上。

The SAPO-34 molecular sieve was synthesized by hydrothermal method and the optimal crystallization time,crystallization temperature and initial gel ratio of SAPO-34 molecular sieve were determined.The molecular sieves were characterized by scanning electron microscopy and X-ray diffraction to determine the SAPO-34 molecular sieve with good morphology and high crystallinity.The Pd/SAPO-34 composite catalyst was prepared by impregnation method using SAPO-34 molecular sieve as carrier,and the Pd/SAPO-34 composite catalyst was characterized by scanning electron microscopy,transmission electron microscopy,temperature-programmed reduction,X-ray photoelectron spectroscopy and X-ray diffraction spectroscopy.The characterization was carried out to determine that the morphology of the SAPO-34 molecular sieve loaded palladium was still regular and complete,and the dispersion degree was better.The catalytic activity center was Pd^(0).The Pd/SAPO-34 composite catalyst was used to catalyze the synthesis of 2-methyl-4-amino-5-aminomethyl pyrimidine intermediate of vitamin B_(1).The results showed that Pd/SAPO-34 composite catalyst has good catalytic effect and can make the conversion and selectivity of the reaction reached more than 99%.