【摘要】 采用浸渍法制备负载KF固体碱催化剂,应用于苯脲和甲醇制备苯氨基甲酸甲酯的反应,考察了氧化物载体、卤化钾种类对催化剂性能的影响,KF/Al2O3催化剂显示出良好的催化活性和苯氨基甲酸甲酯的选择性。通过对KF/Al2O3催化剂中KF的负载量和催化剂焙烧温度的研究发现,在500℃焙烧4 h、负载质量分数50%KF的催化剂能够更好地促进MPC生成,苯脲转化率和苯氨基甲酸甲酯选择性分别达到96.5%和86.3%。XRD分析表明,KF与Al2O3之间存在较强的相互作用,部分转化为K3AlF6。KF与K3AlF6分别对甲醇的活化和苯脲的选择性起促进作用,两者的协同效应共同促进了目标产物苯氨基甲酸甲酯的生成。更多还原

【Abstract】 The solid alkaline catalysts of supported potassium halides were prepared by impregnation method and used in the methanolysis of phenyl urea with methanol to synthesize methyl N-phenyl carbamate( MPC); the influence of oxide supports and potassium halides on the catalyst performance was investigated. The results indicated that KF / Al2O3 exhibits high catalytic activity and selectivity to MPC; the KF / Al2O3 catalyst containing 50% KF and calcined at 500 ℃ for 4 h performs best in the methanolysis of phenyl urea,over which the conversion of phenyl urea and selectivity to MPC reach 96. 5% and 86. 3%,respectively. The XRD results proved that KF and Al2O3 are partially transformed to K3AlF6 due to the strong interaction between KF and Al2O3. Both KF and K3AlF6 are active for the activation of methanol and selective conversion of phenyl urea; the excellent performance of KF / Al2O3 catalyst in the methanolysis of phenyl urea to MPC can be ascribed to the synergy of KF and K3AlF6.更多还原