Abstract: In the context of carbon peaking and carbon neutrality goals, ethanolamine (MEA) has found widespread application in CO2 removal due to its excellent CO2 capture performance. However, during storage and usage, MEA inevitably undergoes leakage and emission, which cand easily lead to its escape from the liquid phase to the gas phase, posing risks to the environment and human health. To mitigate the adverse effects of MEA on the external environment, it is necessary to achieve the green and resourceful degradation of MEA. In this work,different types of TiO2, including anatase TiO2, P25 TiO2, and rutile TiO2, were employed as supports to prepare three Ag/Ti catalysts (Ag/TiO2-A, Ag/TiO2-P, Ag/TiO2-R) via an impregnation method. These catalysts were then used to investigate the catalytic degradation of MEA coupled with the simultaneous production of ammonia. The study found that compared with the other two catalysts, Ag/TiO2-R catalyst exhibited the highest MEA removal efficiency and NH3 yield. Through characterization and analysis using X-ray photoelectron spectroscopy (XPS), oxygen temperature-programmed desorption (O2-TPD), and hydrogen temperature-programmed reduction (H2-TPR), it was determined that the rutile TiO2 support not only facilitates activation on Ag/TiO2-R catalyst, enhancing its degradation efficiency, but also enabled the loaded Ag to exist in an oxidized state on the catalyst. This phenomenon was attributed to the presence of more lattice defects on Ag/TiO2-R, which enhanced the anchoring effect of the catalyst, promoting the loaded silver to exist in an oxidized state. The presence of oxidized silver facilitated the cleavage of C-N bonds during MEA degradation, thus improving the NH3 yield. Therefore, the Ag/TiO2-R catalyst prepared with rutile TiO2 support exhibited the optimal catalytic performance, it achieved complete degradation of MEA at 270℃, and when the reaction temperature reached 300℃, the yields of the products NH3 and CO2 were 80% and 97%, respectively.

Key words: Ag2O, rutile, lattice defect, MEA, catalytic degradation

摘要： 在“双碳”战略背景下，乙醇胺(MEA)由于其优异的CO2捕集性能，在气体脱碳领域得到广泛应用。然而，MEA在储存和使用过程中不可避免地会发生逃逸现象，即从液相中溢出到气相，进而对生态环境及人体健康构成潜在危害。为降低MEA使用过程中对外界造成的不利影响，实现其绿色资源化降解。本研究以锐钛矿型TiO2、P25型TiO2及金红石型TiO2为载体，通过浸渍法制备出三种晶型的Ag/Ti催化剂(Ag/TiO2-A, Ag/TiO2-P, Ag/TiO2-R)，并将其应用于MEA的催化降解及协同产氨研究。研究发现，以金红石型TiO?为载体制备的Ag/TiO2-R催化剂，其MEA去除率与NH3产率均显著高于另外两种晶型的催化剂。通过X射线电子能谱(XPS)、氧气程序升温脱附(O2-TPD)及氢气程序升温还原(H2-TPR)等表征分析得出，金红石型TiO2载体不仅能促进Ag/TiO2-R催化剂对氧的活化，从而提升降解效率；还能使负载的Ag在催化剂上以氧化态的形式存在。这是因为Ag/TiO2-R催化剂上存在更多的晶格缺陷，这些晶格缺陷增强了催化剂对Ag的锚定作用，使负载的Ag趋近于氧化态；而氧化银的存在可有效促进MEA降解过程中C-N键的断裂，提升NH3的产率。因此，采用金红石型TiO2负载的Ag/TiO2-R催化剂催化降解效果最好，在270℃可实现MEA的完全降解，当反应温度达到300℃时，产物NH3和CO2的产率分别达到80%与97%。

关键词: 氧化银, 金红石, 晶格缺陷, 乙醇胺, 催化降解