纳米UO_(2) 的制备及其催化去除NO的性能

Preparation of UO_(2) Nanocrystal and Its Catalytic Removal of NO

铀氧化物在烃类的选择氧化、有机污染物的氧化消除、NO的选择还原等多种环境污染物的去除反应中,均表现出良好的催化性能。UO_(2)的熔点高达2840℃,热稳定性高。本研究选用不同还原剂,采用改进的水热合成法制备不同尺寸的球形UO_(2)纳米晶,对其进行XRD、SEM、BET、H_(2)-TPR和O_(2)-TPO等表征,考察其催化还原NO的性能。结果表明,UO_(2)的尺寸影响催化剂的催化活性,尺寸较大的U-300在400℃,NO转化率达到最大。

Uranium oxides exhibit good catalytic performance in the removal of a variety of environmental pollutants,such as in the selective oxidation of hydrocarbons and the oxidation to eliminate of organic pollutants,the selective reduction of NO,and so on.The melting point of UO_(2) is up to 2840℃,and it has thermal stability.UO_(2) nanocrystals were prepared by modified hydrothermal route with different organic amines.Then it was characterized by XRD,SEM,HRTEM and H_(2)-TPR,etc.Their catalytic performance for reduction NO by CO was evaluated.The results showed that the size of UO_(2) affected the catalytic activity of catalyst,and the larger size of U-300 reached the maximum NO conversion at 400℃.