SnO_(x)-CeO_(x)/沥青基球形活性炭催化剂选择性催化还原NO的脱硝性能  

Denitration Performance of SnO_(x)-CeO_(x)/Pitch-Based Spherical Activated Carbon Catalysts for Selective Catalytic Reduction of NO

作　　者：王艳莉[1] 崔均烜 褚晨婕 詹亮[1] WANG Yanli;CUI Junxuan;CHU Chenjie;ZHAN Liang(State Key Laboratory of Chemical Engineering,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学化工学院,化学工程联合国家重点实验室,上海200237

出　　处：《华东理工大学学报（自然科学版）》2023年第2期153-160,共8页Journal of East China University of Science and Technology

基　　金：国家自然科学基金(51472086,51002051,22075081,20806024);上海市自然科学基金(12ZR1407200)。

摘　　要：以高软化点石油沥青原料制备的沥青基球形活性炭(PSAC)为载体,采用浸渍法负载锡、铈氧化物制备SnO_(x)-CeO_(x)/PSAC系列催化剂,考察催化剂在低温下的脱硝性能,并采用N2吸附/脱附、X射线衍射(XRD)、X射线光电子能谱(XPS)等方法对催化剂进行表征。结果表明,在CeO_(x)/PSAC催化剂中添加SnO_(x)后催化剂的脱硝活性显著增加,但随着金属担载量(质量分数)增加,脱硝活性呈现先升高后降低的趋势,Sn、Ce担载量分别为5%和13%的SnO_(x)-CeO_(x)/PSAC(以Sn(5%)Ce(13%)/PSAC表示)催化剂具有最高的脱硝活性,在该催化剂条件下,100~300℃时可得到最高的NO转化率(98%)。添加SnO_(x)后,CeO_(2)在载体表面的分散性得到提高,由于Sn^(4+)替代Ce^(4+)掺杂于立方相CeO_(2)晶格中形成固溶体,因而催化剂的脱硝活性提高。此外,与单组分铈催化剂相比,Sn(5%)Ce(13%)/PSAC催化剂具有较好的抗SO_(2)毒化性能。Pitch-based spherical activated carbon(PSAC)is widely used in biomedicine,environmental protection and other practical fields because of its advantages of high specific surface area,high mechanical strength,high packing intensity and low fluid resistance.In this study,series of SnO_(x)-CeO_(x)/PSAC catalysts were prepared by the impregnation method using PSAC prepared from high softening point petroleum pitch as the support.Their catalytic performances were evaluated in the low-temperature selective catalytic reduction(SCR)of NO with NH_(3).The catalysts obtained were characterized by nitrogen adsorption/desorption,X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).The results show that SnO_(x)-CeO_(x)/PSAC catalyst exhibits higher SCR activity than CeO_(x)/PSAC catalyst,and the NO conversion rate first increases and then decreases with the increase of metal loading.The Sn(5%)Ce(13%)/PSAC catalyst exhibits the highest NO removal activity,and the highest NO conversion rate reaches 98%in the temperature range of 100~300℃.This is mainly due to the improved dispersion of cerium oxide on the surface of PSAC in the presence of SnO_(x),and the formation of a solid solution between SnO_(x) and CeO_(x) with a fluorite-type structure probably caused by the incorporation of Sn4+into the crystal lattice of CeO_(2).Furthermore,a certain amount of Ce3+and a high percentage of chemisorbed oxygen exist on the catalyst surface because of the synergistic effect between tin and cerium oxides.These factors result in the excellent NH_(3)-SCR performance of the Sn(5%)Ce(13%)/PSAC catalyst.Compared with CeO_(x)/PSAC catalyst,SnO_(x)-CeO_(x)/PSAC catalyst exhibits a higher resistance to SO_(2) poisoning.The NO conversion rate of the Sn(5%)Ce(13%)/PSAC catalyst retains at 80%at 260℃after the introduction of SO_(2) in the feed gas for 420 min.

关 键 词：球形活性炭 SnO_(x)-CeO_(x) 选择性催化还原 一氧化氮 脱硝 

分 类 号：TQ032[化学工程]