WO_3/ZrO_2固体超强酸改性及在酯化反应中应用研究

Study on Modification of Solid Superacid WO_3/ZrO_2 and its Application to Esterification

为进一步提高WO3/ZrO2固体超强酸催化活性和稳定性,采用共沉淀法分别制备Ce和Mn改性WO3/ZrO2催化剂。通过XRD、Raman等方法对改性前后催化剂进行表征,由相应图谱分析Ce和Mn引入对催化剂晶型结构和表面性质的影响;并将改性后催化剂用于丙酸和正丁醇的酯化反应考察其催化性能,同时确定合成丙酸正丁酯的最佳工艺条件。结果表明,Ce或Mn的引入能更好地抑制焙烧时ZrO2晶粒长大,使晶粒粒度更加细化,但是没有改变WO3/ZrO2催化剂的物相结构;与WO3/ZrO2相比,Ce或Mn掺杂后催化剂活性明显提高。

In order to improve the catalytic activity and stability of the solid superacid catalyst WO3/ZrO2, the Ce and Mn-modified WO3/ZrO2 solid superacids were respectively prepared by co-precipitation method. WO3/ZrO2 and modified WO3/ZrO2 catalysts were characterized by means of XRD and Raman. The effects of modification on the crystalline structure and surface property of the catalysts were studied with the corresponding spectra. The catalytic performance of modified WO3/ZrO2 using for synthesizing n-butyl propionate was investigated, and the optimum parameters of synthesis were determined. The results show that the Ce or Mn doped tungstated zirconia could prevent the grain growth and make crystallite size decrease, however, no change in the structure of WO2/ZrO2 catalyst was found. Compared with WO3/ZrO2 solid superacid, Ce, Mn-modified catalysts show higher catalytic activity.