本文選題：揮發(fā)性有機(jī)物 + 催化燃燒�。� 參考：《中國石油大學(xué)(華東)》2015年碩士論文

【摘要】：揮發(fā)性有機(jī)化合物是一類重要的大氣污染物,嚴(yán)重影響人們的日常生活和工作。催化燃燒法是應(yīng)用廣泛的處理技術(shù),其核心是高效催化劑的開發(fā)。鈣鈦礦催化劑表現(xiàn)出較高的催化活性,其應(yīng)用的關(guān)鍵是載體的有效選擇。本論文將以鈣鈦礦La_(0.8)Ce_(0.2)MnO_3為活性組分,氧化物多孔材料為載體制備負(fù)載型催化劑,研究氧化物類載體對(duì)負(fù)載型鈣鈦礦催化燃燒VOCs的影響,并采用XRD、SEM、H_2-TPR、BET等微觀分析手段對(duì)催化劑進(jìn)行表征,分析氧化物類載體在催化燃燒過程中的載體效應(yīng),主要結(jié)論為:催化劑載體性質(zhì)影響催化劑燃燒甲苯的反應(yīng)活性。鈣鈦礦經(jīng)氧化物類載體負(fù)載后,其活性順序?yàn)長a/CeO_2La/TiO_2La/Al_2O_3。在鈣鈦礦負(fù)載量為15%,焙燒溫度為600℃時(shí),La/CeO_2催化劑起燃溫度為130℃,完全轉(zhuǎn)化溫度為240℃;經(jīng)表征發(fā)現(xiàn),600℃時(shí)鈣鈦礦以無定形狀態(tài)存在,具有豐富的缺陷位,有利于甲苯的催化燃燒反應(yīng)。對(duì)于氧化物類載體,雖然載體較大的比表面積和孔結(jié)構(gòu)有利于甲苯催化燃燒反應(yīng),但真正決定催化劑活性高低的因素是載體的儲(chǔ)氧性能。通過調(diào)控模板劑(CTAB)與Ce~(4+)的摩爾比制備了一系列介孔La/CeO_2催化劑。研究發(fā)現(xiàn),當(dāng)CTAB/Ce~(4+)摩爾比為10:1時(shí),載體的比表面積最大,負(fù)載鈣鈦礦后,催化活性也最高。通過表征發(fā)現(xiàn),不同催化劑在儲(chǔ)氧性能相當(dāng)?shù)那闆r下,載體較大的比表面積有利于催化劑的傳質(zhì)過程,從而提高催化劑燃燒甲苯活性。采用水熱法成功合成了不同形貌CeO_2載體。負(fù)載鈣鈦礦后,以納米粒子La/CeO_2活性最高,起燃溫度為130℃,完全轉(zhuǎn)化溫度為240℃;表征結(jié)果顯示,不同形貌催化劑表現(xiàn)出不同的儲(chǔ)氧性能。棒狀CeO_2比表面積較大,但其較高的還原溫度導(dǎo)致其低溫活性較差;立方體CeO_2具有較好的儲(chǔ)氧性能,但其比表面積小,晶粒尺寸較大,限制了催化活性的提高;納米粒子La/CeO_2擁有更多的氧空位和高活性氧物種,且其比表面積較大,粒徑較小,因此其催化活性最高。通過考察Ce_xTi載體負(fù)載La_(0.8)Ce_(0.2)MnO_3催化劑的活性發(fā)現(xiàn),在Ce/Ti比為0.5:1,鈣鈦礦負(fù)載量為20%,焙燒溫度為600℃時(shí),催化劑的起燃溫度為120℃,完全轉(zhuǎn)化溫度為235℃,優(yōu)于單一氧化物負(fù)載鈣鈦礦活性。通過表征發(fā)現(xiàn),當(dāng)Ce/Ti比為0.5:1時(shí),載體形成的Ce_xTi_(1-x)O_2固溶體是其活性提高的根本原因;且Ce_(0.5)Ti較大的比表面積和表面酸性,有利于活性組分的分散以及載體和活性組分的協(xié)同作用,從而進(jìn)一步提高活性。
[Abstract]:Volatile organic compounds (VOCs) are important atmospheric pollutants which seriously affect people's daily life and work. Catalytic combustion is a widely used treatment technology, the core of which is the development of high efficient catalyst. Perovskite catalysts exhibit high catalytic activity, and the key to their application is the effective selection of carriers. In this paper, the supported catalysts are prepared by using perovskite La _ Tip _ (0.8) C _ (0.2) MNO _ (3) as active component and porous oxide material as carrier to study the effect of oxide support on the catalytic combustion of VOCs in supported perovskite. The catalyst was characterized by means of XRDX SEMHH _ 2-TPR-BET, and the support effect of oxide support in the process of catalytic combustion was analyzed. The main conclusions were as follows: the properties of catalyst carrier affected the reaction activity of catalyst for toluene combustion. The order of activity of perovskite loaded with oxide carrier is La / CEO _ 2La / TIO _ 2O _ 2La-Al _ 2O _ 2O _ 3. When the amount of perovskite loading is 15 and the calcination temperature is 600 鈩，

本文編號(hào)：1997630