本文選題：OMS-2 + Ce-OMS-2�。� 參考：《北京化工大學(xué)》2015年碩士論文

【摘要】：眾所周知,對于人類賴以生存環(huán)境而言,臭氧起到雙刃劍的作用。在平流層,臭氧能夠抵擋紫外線直接照射地球,是大自然的天然保護(hù)屏障；然而在靠近地表處,臭氧的危害作用十分大,會對人體的皮膚,免疫系統(tǒng)以及神經(jīng)系統(tǒng)等產(chǎn)生不同程度的影響。近地表的臭氧主要來源于水處理的尾氣和打印機(jī)等辦公設(shè)備。催化分解臭氧方法由于其安全、經(jīng)濟(jì)、高效的特點(diǎn),受到廣泛關(guān)注,其中錳氧化物是最有效的去除臭氧的催化劑。隱錳鉀礦(OMS-2)是一種由[Mn06]八面體鏈內(nèi)共棱,鏈間共頂角氧構(gòu)筑的孔徑為0.46nm的一維孔架結(jié)構(gòu)的錳氧化物。OMS-2骨架中存在不同價態(tài)的錳離子,能提供較大的比表面積以及較高的抗?jié)裥阅?有利于臭氧的催化分解。本文采用水熱合成的方法制備了一系列OMS-2和金屬摻雜的M-OMS-2催化劑,并考察了其高濕度條件下對臭氧的分解性能。通過XRD、 Raman、XAFS、BET、SEM、H2-TPR和ICP等表征手段對催化劑進(jìn)行了結(jié)構(gòu)和性能表征。結(jié)果表明：在單組分OMS-2催化劑中,采用乙酸錳為前驅(qū)體合成的OMS-2-Ac催化劑在相對濕度為90%的條件下,表現(xiàn)出比較優(yōu)越的臭氧催化活性,轉(zhuǎn)化率為80%左右,性能優(yōu)于以硝酸錳合成的OMS-2-NO3和以氯化錳合成的OMS-2-Cl催化劑。合成過程中乙酸根的存在能夠阻止錳氧化物粒子之間的聚集,提供更多的表面缺陷位,OMS-2-Ac催化劑表面豐富的Mn3+是催化劑性能優(yōu)越的關(guān)鍵因素。在金屬摻雜的M-OMS-2催化劑中,以硝酸鈰銨為前驅(qū)體合成Ce-OMS-2催化劑具有最優(yōu)的臭氧分解性能,在相對濕度為90%條件下,6小時內(nèi)臭氧的轉(zhuǎn)化率基本為100%。與其他Co-OMS-2、Ni-OMS-2、Cu-OMS-2和Fe-OMS-2催化劑相比較,Ce-OMS-2的結(jié)構(gòu)發(fā)生畸變,Mn-Mn的配位不完全,有較大的比表面積,能夠暴露更多的表面活性位；催化劑表面具有豐富的Mn3+和表面氧,有利于02*的脫附,促進(jìn)臭氧的分解。Ce-OMS-2催化劑在相對濕度為90%,體積空速高達(dá)600000h-1的條件下,表現(xiàn)出優(yōu)越的臭氧催化分解活性,因此對于高濃度臭氧尾氣的處理具有很高的應(yīng)用價值。
[Abstract]:As we all know, ozone plays a double-edged role for human living environment.In the stratosphere, ozone acts as a natural protective barrier to nature by shielding itself from direct ultraviolet radiation; however, near the surface, ozone is so harmful that it does harm to the skin of the human body.The immune system and the nervous system have varying degrees of influence.Ozone near the surface mainly comes from exhaust gas from water treatment and office equipment such as printers.The catalytic decomposition of ozone has attracted much attention because of its safety, economy and efficiency. Manganese oxide is the most effective catalyst for ozone removal.OMS-2) is a manganese ion with different valence states in the framework of manganese oxide. OMS-2, which is constructed by co-edged in [Mn06] octahedron chain and coparietal oxygen between chains, has a one-dimensional pore structure of 0.46nm.It can provide large specific surface area and high moisture resistance, which is beneficial to the catalytic decomposition of ozone.In this paper, a series of OMS-2 and metal-doped M-OMS-2 catalysts were prepared by hydrothermal synthesis.The structure and properties of the catalyst were characterized by XRD, Ramanlum ICP, BETS, SEMX, H2-TPR and ICP.The results showed that the OMS-2-Ac catalyst synthesized with manganese acetate as precursor showed superior ozone catalytic activity under 90% relative humidity, and the conversion rate was about 80%.The performance of the catalyst is superior to that of OMS-2-NO3 synthesized by manganese nitrate and OMS-2-Cl synthesized by manganese chloride.In the process of synthesis, the presence of acetate can prevent the aggregation of manganese oxide particles, and providing more surface defect sites and abundant Mn3 on the surface of OMS-2-Ac catalyst is the key factor for the superior performance of the catalyst.In the metal-doped M-OMS-2 catalyst, the synthesis of Ce-OMS-2 catalyst with ammonium cerium nitrate as the precursor has the best ozone decomposition performance, and the conversion rate of ozone is almost 100 in 6 hours under 90% relative humidity.Compared with other Co-OMS-2Ni-OMS-2Mo Cu-OMS-2 and Fe-OMS-2 catalysts, the structure of Ce-OMS-2 is distorted. The coordination of Ce-OMS-2 is incomplete and has a larger specific surface area, which can expose more surface active sites, and the surface of the catalyst is rich in Mn3 and surface oxygen, which is conducive to the desorption of 0.2 *.Ce-OMS-2 catalyst for promoting the decomposition of ozone has excellent catalytic activity of ozone decomposition under the condition of 90 relative humidity and high volume space velocity (600000h-1), so it has a high application value for the treatment of high concentration ozone tail gas.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X51;O643.36

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本文編號：1758873