【作者】 王立刚；

【导师】 沈美庆；

【作者基本信息】 天津大学 ， 化学工艺， 2007， 硕士

【摘要】 随着人们对含氯挥发性有机化合物(CVOCs)危害越来越多的关注,针对CVOCs处理方法也取得了很大的进展。其中,催化燃烧法具有操作温度低、能耗小、净化彻底等优点,使其成为重要的净化手段。V-W/Ti体系催化剂由于V、W较高的活性成为催化去除CVOCs的研究热点。本文以1,2-二氯乙烷催化燃烧为模型反应,研究不同晶型TiO2载体对催化活性的影响并进行筛选。考察V、W浸渍顺序和不同V、W原子比制备的六种催化剂,揭示制备工艺对1,2-二氯乙烷催化性能的影响。并利用BET、XRD、TPR、FTIR研究样品的比表面、晶相、氧化能力及表面酸性,用Raman表征手段解释催化剂活性下降的原因。研究表明,500℃焙烧得到是以锐钛矿晶型为主的TiO2载体,以其制备的催化剂催化性能更优。在不同V、W浸渍顺序制备的样品中,采用共浸渍方法的样品中强B酸量多、氧化能力强,催化活性明显。不同V、W原子比催化活性评价中,原子比为3:1的样品表面虽具有大量的中强B酸,但是活性组分V部分以V2O5的晶型存在,氧化性能较差,导致催化活性最低;原子比为1:1的催化剂在酸强度和氧化能力方面都优于其它两种催化剂,使此催化剂表现了较好的活性。根据实验结果,初步探讨了1,2-二氯乙烷的反应机理。催化剂的稳定性实验表明,催化剂表面形成积炭(W-V/Ti)及TiO2载体的晶型转变(V3W1)均会导致催化剂稳定性下降。更多还原

【Abstract】 As the more attention to the Chlorinated Volatile Organic Compounds (CVOCs), the methods of dealing with CVOCs had the well developed. Among the various disposal methods, catalytic combustion has advantages of low temperature operation, low costs and no by-products which became an important method. The V-W/Ti system became the hotspot because of higher activity of vanadium and tungsten.In this paper, catalytic combustion of 1,2-dichloroethane is a model reaction. Researching of TiO2 support on catalytic activity and then comparing with them. Compared with V, W impregnating order and atomic ratio of V/W to investigate on 1,2-dichloroethane catalytic performance. Characterization of BET, XRD, TPR, and FTIR to research the surface area, crystalline, oxidation ability and acid of catalysts. The Raman spectra to explain catalytic stability for the decline.The research shows that performance of 500℃for TiO2 prepared of catalyst is better than that 700℃for TiO2. This can be attributed to the former has higher content of anatase crystal type, which has higher chemical activity. In different impregnating order prepared of the samples, the simultaneous impregnation has amount of medium-strong B acid and strong oxidation, the catalytic activity is obviously. During the evaluation of catalytic activity with different V/W atomic ratio, atomic ratio of 3 with a large amount of B acid, however, the V in partial with V2O5. Furthermore, the oxidation is week which leads to worst activity. Atomic ratio of 1 is better than other two in acid strength and oxidation which has better performance on activity. Based on the experiment results to study preliminarily on the reaction mechanism of 1,2-dichloriethane. In the experiment of stability, carbon deposition (W-V/Ti) and crystal transformation (V3W1) are lead to a decline in stability.更多还原