Preparation of SBA-15 as catalyst support for VOC oxidation

• Main Authors: Yu-Hao Chang, 章育豪
• Other Authors: 魏銘彥
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/03128449128783210794

碩士 === 國立中興大學 === 環境工程學系所 === 96 === Among all the air pollutants, Volatile Organic Compounds (VOCs) are in terms of fugitive emissions, and VOC are by far the most abundant and harmful pollutant affecting both the human body and the environment. In the atmosphere, VOCs may produce photochemical smog and ozone through a serious of photodegradation and oxidation process, and the air quality deterioration is becoming the serious environmental problem. Nowadays, VOC have been the control focal target of air pollutants in every country of the world. A catalytic incinerator is one of the best skills in control of VOC. Effective diffusion coefficients of gaseous molecules were decided by the porous diameter of the catalyst supports, while removing the gas pollutants. In the present case, the raising of average pore size diameter results: the diffusion of metal precursors into the pores was improved during the catalyst preparation; and as a result the adsorption capacity of the catalyst was increases and the catalytic efficiency was enhanced. This research was mainly focused on the preparation of mesoporous support, SBA-15, contained high specific surface area and uniform pore size, and then evaluated the catalytic activity with various catalysts prepared by different supports, various metals, and different catalyst preparations. Characterization of catalyst was done by using the techniques BET, XRPD, SAXS, FESEM, TEM, ICP-MS. The experimental results show that compared the catalytic activity with different catalyst supports, SBA-15-supported catalyst showed the higher catalytic activity than commercial Al2O3-supported catalyst. It was due to the uniform mesoporous-structure and high mass transfer limitation of SBA-15 that gas molecules were easily diffused into the pores to react with active sites. The catalytic activity of various SBA-15 supported single metallic catalysts on VOC oxidation follows the sequence of Cu＞Ni＞Co, and the catalytic activity of SBA-15 supported bimetallic catalysts is in the order of Mn-Cu＞Co-Cu＞Ce-Cu＞Ni-Cu. Among the redox tests for VOC and NO removal simultaneously over Mn-Cu/SBA-15 with various VOCs, VOC including aromatic ring showed the better reaction efficiency than others, and the activity of reductants is in the order of toluene＞benzene＞formaldehyde＞ethanol＞methanol. The obtained results indicated that the impregnation process could successfully manufacture the SBA-15-supported nanocatalysts which could be appied to remove VOC and NO by catalystic incineration.