La和Bi对乙炔与甲酸甲酯加氢酯化合成丙烯酸甲酯的镍基催化剂性能的影响(英文)

在２２０℃和５０－６０大气压条件下，利用固定床对ＮｉＯ／ＳｉＯ２、ＮｉＯ／Ａｌ２Ｏ３、ＮｉＯ－Ｌａ２Ｏ３／Ａｌ２Ｏ３和ＮｉＯ－Ｂｉ２Ｏ３／Ａｌ２Ｏ３催化剂上的乙炔与甲酸甲酯加氢酯化合成丙烯酸甲酯进行了研究。镍基催化剂对乙炔的加氢酯化合成丙烯酸甲酯具有很好的活性。用浸透法制备的Ｍｏ／ＳｉＯ２催化剂的活性和丙烯酸甲酯的选择性均比离子交换法差。ＮｉＯ／Ａｌ２Ｏ３催化剂用Ｌａ或Ｂｉ改性后，其催化活性大大提高。ＸＰＳ、ＸＲＤ和ＴＰＲ结果表明，当催化剂用Ｌａ或Ｂｉ改性后，ＮｉＯ的晶粒明显减小，催化剂表面的Ｎｉ／Ａｌ原子比增大，催化剂的第二个还原峰温大大降低。

EFFECTS OF La AND Bi ON THE CATALYTIC PERFORMANCE OF SUPPORTED NICKEL CATALYST FOR ACETYLENE HYDROESTERIFICATION TO METHYL ACRYLATE

The catalytic hydroesteritication of acetylene over NiO/Al2O3 and NiO/SiO2 prepared by impregnation or ion-exchange as well as La2O3- and Bi2O3-promoted NiO/Al2O3 has been studied in a fixed bed reactor at 220 and under 50 atm~60 atm. Ni-based catalyst was found to be active and selective to methyl acrylate (MA). NiO/SiO2 (imp.) catalyst was less active and selective than that prepared by ion-exchange method. The catalytic activity of NiO/Al2O3 (imp.) was greatly improved by adding La or Bi. XPS and XRD results suggest that the size of crystallite of nickel oxide was reduced by adding La or Bi. The surface Ni/Al atomic ratio increased When NiO/Al2O3 (imp.) was modified by La or Bi. TPR results showed that When the suppert was modified with La or Bi, the secon reduction temperature of catalyst was decreased significantly.