纯相钼酸酐氮化合成技术及表征

Synthesis technology and characterization of pure phase molybdenum acid anhydridenitridation

以钼酸铵为原料,采用高温焙烧法制备颗粒状催化剂前驱体钼酸酐;以氮氢混合气为氮化剂合成氮化钼。考察空速、程序升温速率及氮化终温对氮化钼比表面积的影响,并通过SEM、XRD、BET对纯相氮化钼及前驱体钼酸酐表征。结果表明,一定条件下,当空速为42 000 h-1时,产物的比表面积最大,为129.2 m^2·g^(-1);当升温速率为1.0℃·min-1时,比表面积最大,为135.6 m^2·g^(-1);当氮化终温为750℃时,比表面积达到52.78 m^2·g^(-1)。纯相钼酸酐氮化条件温和、原料成本低。

Granular catalyst precursor,molybdenum acid anhydride,was prepared by high temperature calcinations with ammonium molybdate as raw material. With nitrogen and hydrogen mixture as nitriding agent,molybdenum nitride was synthesized. Effects of space velocity,programmed temperature rise rate and final temperature of nitride on the specific surface area of molybdenum nitride were investigated. By means of SEM,XRD and BET,molybdenum nitride and its precursor molybdenum acid anhydride were characterized. Research results show that under a certain conditions,the product has the largest surface area of 129. 2 m2·g^（-1） when the space velocity is 42 000 h-1; the surface area of 135. 6 m2·g^（-1） is largest when the heating rate is 1. 0 ℃ ·min-1; the surface area reaches 52. 78 m2·g^（-1） when the terminal nitriding temperature is 750 ℃. The nitridation condition of pure phase molybdenum acid anhydride is mild and the raw material cost is low.