The Development Of The Anodic Oxidation Monolith Catalysts And Application In VOCs Catalytic Combustion System

Volatile organic mcompounds (VOCs) are considered as key contributors to pollution, because they can function as precursors of photochemical smog and harm heavily the health of people. The catalytic oxidation of VOCs to CO2 and H2O is regarded as the most promising method because of its low reaction temperature and high catalytic efficiency. However, the traditional catalysts exhibit high pressure drop, poor heat and electric conduction. Therefore, a structured catalyst with low pressure drop, good heat and electric conduction, easy molding, high activity has attracted research’s attention. In this study, novel anodic oxidation plate-type structured catalysts were used for catalytic oxidation VOCs under low and high temperature to evaluate their performance, and analyzed the reaction mechanisms.In the high temperature reaction system, toluene catalytic oxidation was selected as the research object. The influence on catalytic performance of different competitive impregnation methods and different competitive adsorbents with different acidity were discussed, and prepared the catalyst Pt/y-Al2O3 with high dispersion and low Pt loading amount. According to the Electronic probe microanalysis analyzer (EPMA), scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), H2-TPR analysis, lactic acid was regarded as the best competitive adsorbent and co-aompetive impregnation was better impregnation method. The mechanisms of the two competitive methods were proposed. Moveover, potassium metal was supported into the catalysts as auxiliaries to modify the catalysts. The influence of different impregnation methods of potassium and potassium loading amount on performance were researched. It could be seen that potassium benefited for Pt distribution and decreased Pt reduction temperature, which highly decrease reaction temperature. Comparing impregnation methods of potassium, the step impregnation showed better catalytic performance. Furthermore, the effect of steam and chlorine on catalytic activity was discussed. The results showed that the modified catalysts had good steam resistance and the chloride resistance still needed to be improved.In the low temperature reaction system, the novel AlOOH support showed stronger adsorption to formaldehyde because of the large amount of hydroxy and realized the application of catalysts Pt/AlOOH in low temperature formaldehyde catalytic oxidation. To optimize further the catalysts preparation technology, the different impregnation methods,including normal impregnation, ultrasonic impregnation and co-impregnation were compared. The preparation technologies of every method were researched, and co-impregnation was regarded as the best method because the hot water treatment occurred simultaneously during the impregnation process. The optimized catalyst could catalyze formaldehyde of 200ppm at 60℃.