作　　者： ; ; (等）;

机构地区： 广州大学环境科学与工程学院环境科学系

出　　处： 《光谱学与光谱分析》 2002年第5期755-757,共3页

摘　　要： 采用漫反射红外光谱原位考察了 2 98～ 773K范围H2 O ,NH3 和NO在SAPO 34分子筛上的吸附行为。结果表明 ,SAPO 34对水的吸附是可逆的 ,对NH3 和NO的吸附则是不可逆的。吸附水在 6 2 3K完全脱附 ,脱水后的分子筛在 36 2 5～ 36 0 0cm-1出现表征桥式羟基 (Si OH Al)的特征峰。发现SAPO 34对NH3 和NO均有良好的吸附 催化活性。吸附NH3 后 ,桥式羟基消失 ,位于 3135 ,30 32和 1399cm-1处在 42 3K时出现三个吸收峰 ,在 6 73K达最大 ,且峰高分别是SAPO 34骨架峰高的 3 9,1 7和 6 7倍 ;吸附NO后 ,在室温下位于 136 4cm-1也观测到一强而尖锐的峰 ,其强度与骨架峰强度相当。对这些峰进行归属表明 ,吸附NH3 和NO后产生了新的物种NO-3 。 The adsorption of H 2O, NH 3 and NO in molecular sieve SAPO-34 was studied by in situ DRIFTS at temperatures from 298 K to 773 K. The results show that the phenomenon of adsorption is reversible for H 2O, but not for NH 3 and NO. The water in SAPO-34 is absolutely deadsorbed at 623 K and the bridged Si-OH-Al group is observed at 3 625-3 600 cm -1. It is found that SAPO-34 displays good adsorption-catalysis activity for NH 3 and NO. After adsorbing NH 3, the bridged hydroxyls disappear, but three peaks appear at 3 135, 3 032 and 1 399 cm -1 at 423 K, and reach their climax at 673 K.The height of the peaks are 3.9, 1.7 and 6.7 times as much as SAPO-34 framework peak′s, respectively. A strong and sharp peak is also observed at 1 364 cm -1 after NO adsoption at room temperature, and it exhibit approximately the same intensity with the framework peak. Analysis of these peaks indicate that there could produce new species NO - 3.

关 键 词： 分子筛 吸附性能 原位漫反射红外光谱 吸附行为 水 一氧化氮 氨

领　　域： [理学] [理学]