载体及NiO负载方法对乙炔加氢酯化合成丙烯酸甲酯反应的影响

在5－6MPa、220℃下考察了用浸渍法制备的NiO/SiO2(NiO/SiO2(imp.))和NiO/Al2O3（NiO/Al2O3(imp.))催化剂及用离子交换法制备的NiO/SiO2(NiO/SiO2(ex))催化剂上乙炔加氢酯化合成丙烯酸甲酯（MA）的催化活性和选择性。试验结果表明用离子交换法制备的NiO/SiO2(ex.）催化剂，其催化活性和选择性均高于浸渍法制备的NiO/SiO2(imp.)。从TPR谱图看，NiO/SiO2（ex.)和NiO/SiO2(imp.)都只有一个还原峰，而前者的还原温度较后者高。NiO/Al2O3(imp.)在NiO含量低时只有一个高温还原峰，含量高时出现两个还原峰，其低温还原峰对应的是与载体作用较弱的NiO晶粒的还原，而高温还原峰相当于载体作用较强的NiO晶粒的还原。

EFFECT OF SUPPORT AND METHOD OF LOADING ON THE CATALYTIC PERFORMANCE OF SUPPORTED NICKEL CATALYST FOR ACETYLENE HYDROESTERIFICATION TO METHYL ACRYLATE

The catalytic hydroesterification of acetylene over supported NiO/Al2O3 and NiO/SiO2 catalysts prepared by impregnation and ion-exchange (NiO/Al2O3(imp.), NiO/SiO2(imp.),and NiO/SiO2(ex.))has been studied in a fixed bed reactor at the conditions of 220 ℃ and 5～6　MPa.The results show that the NiO/Al2O3(imp.) catalyst is very active and selective to methyl acrylate,but the NiO/SiO2(imp.) catalyst is less active and selective than that prepared by ion-exchange NiO/SiO2(ex.).TPR results show that NiO/Al2O3(imp.),NiO/SiO2(imp.)and NiO/SiO2(ex.) have different reduction temperature,which suggests that the dispersion degree of NiO over support is different.