摘要
氧化铌在含水体系中表现出强酸性,因而它在众多的含水反应中得到越来越多的应用。酸浸渍处理后的铌酸在一定条件下可变成结晶型氧化铌。它不仅酸量大,酸强度高,而且酸性可保持到较高的温度。我们用硫酸溶解的方法处理铌酸,在较低温度下得到了结晶氧化铌。
β-Nb2O5 crystal was prepared by the hydrolysis of Nb2O5 solution in concentrated H2SO4 and then by crystallization at 120℃.The surface of such β-Nb2O5 crystal showed a strong acidic character as compared with the surface acidity of the Nb2O5 treated by the same way as β-Nb2OB crystal but not crystallized, Nb2O5 treated by soaking with 0.5M H2SO4 and 1.0 M H3PO4 respectively,and Nb2O5 treated only by washing with water. The activity and selectivity of β-Nb2O5 crystal as a catalyst for the dehydration of isopropanol and the esterification reaction of acetic acid with ethyl alcohol are higher than those of other four Nb2O5 catalysts mentioned above.
基金
国家自然科学基金
