氧化锶催化性质研究Ⅰ.SrO表面活性中心的TPD研究

CATALYTIC CHARACTER OF SrO Ⅰ TPD STUDY OF SURFACE ACTIVE SITES ON SrO

本文运用吸附二氧化碳、氧气、一氧化碳和正丁胺的ＴＰＤ技术，对ＳｒＯ表面活性中心的种类和分布进行了研究。发现在９２１Ｋ和１１７３Ｋ有二个二氧化碳的脱附峰，且高温脱附峰极大；在４３６Ｋ和６７３Ｋ附近有二个氧的脱附峰，高温脱附峰也很大；在６７３～８７３Ｋ之间有一分布不很明显的一氧化碳脱附峰，但在９７３Ｋ附近有很大的一氧化碳脱附峰；在实验条件下，没有与正丁胺有关的脱附峰出现。这些结果表明了ＳｒＯ表面不但有强和较多的碱中心。

In this paper, TPD (TemperatureProgrammed Desorption) of adsorbed carbon dioxide, oxygen, carbon monoxide and butylamine were used to investigate species and dispersion of active sites on SrO It was found that the desorption peaks of carbon dioxide appeared at 921K and 1173K if carbon dioxide was adsorbed for enough time, otherwise, only one desorption peak of carbon dioxide appeared at 1173K; large desorption peaks for oxygen and carbon monoxide appeared at 673K and 973K, respectively, and small desorption peaks for oxygen and carbon monoxide at 436K and 673￣873K, respectively; but almost no desorption peak related to butylamine was found in TPD figure It suggested that there were solidbase sites, activeoxygen (or oxygen mobility) sites and singleelectron sites on SrO surface Compared with MgO, SrO has very strong basicity, very weak acidity, better supplyrestore oxygen sites and singleelectron characters All those active sites result from the exposed oxygen ions