稀土对磷钒催化剂性能的影响

Effect of Rare Earth Elements on Characterization of V-P Catalyst

用Ｘ射线粉末衍射（ＸＲＤ）、Ｘ光电子能谱（ＸＰＳ）和氨－程序升温脱附（ＮＨ３－ＴＰＤ）等方法研究了添加稀土元素后用钒催化剂的晶相组成及表面性质。将催化剂应用于正丁烷选择氧化制备顺酐，用固定床反应器对催化剂活性进行评价。实验结果表明，磷钒催化剂添加稀土元素后可使正丁烷生成顺酐的产率提高４％～１５％。稀土助催化的作用原理是增加了催化剂表面的酸性。

Phase composition and surface characterization of vanadium-phosphorus catalysts containing rare earth elemetns were investigated by means of X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), NH_3-temperature programmed desorption(NH_3-TPD) and so on. The catalysts were used for the selective oxidation of n-butane to maleic anhydride. Catalytic performance has been carried out in a fixed-bed reactor. Experimental results showed, yield of maleic anhydride is enhanced 4 ～ 15% over vanadium-phosphorus catalysts promoted with rare earth elements than over vanadium-phosphorus catalyst. The main action of promotor is that addition of rare carth elements may increase surface acidity of catalysts.