水分对原位漫反射红外光谱表征的影响及其消除研究

水分在原位漫发射红外光谱研究VOCs的催化氧化实验中严重影响了催化剂上其他物种峰的辨认。分析了体系中水分产生的原因主要有气源中水分、管路中滞留水分、物料中所含水分以及反应产生水分等，针对不同产生途径提出采用不同的脱除方法，主要探讨反应物料中水分的脱除，采用浓硫酸、无水氯化钙和无水硫酸铜、硅胶以及5A分子筛对进气中水分进行脱除，发现5A分子筛的脱除效果较佳。同时发现原位反应池中气相水分也有一定的影响。通过对该反应体系中水分脱除各种方法的比较分析，得出结论：温度和所选干燥剂具有很大影响，5A分子筛的脱水效果最佳，原位池中水分也有一定影响，可通过抽真空的方法来消除或降低。

Influence and Removal of Water on In-situ DRIFTS Characterization

Water influences the recognition of surface species on the catalysts during the catalytic oxidation of VOCs using in-situ DRIFTS. The main reasons for the existence of water in the system were supposed to be water existed in gas cylinders, held in pipelines, carried in raw materials and created in reactions. Different removing methods were provided for corresponding sources. Concentrated H2SO4, anhydrous CaCl2 and CuSO4, silica gel, 5A molecular sieves were used for the removal of water from raw materials. It was found that 5A molecular sieves exhibited perfect effect and that water in the gaseous phase in the in-situ cell had some influence which could be removed or decreased under vacuum. After the comparison of all the removing methods, a conclusion could be made that temperature and the drier adopted had great influence, and 5A molecular sieves showed the best effect in the dehydration.