摘要
采用溶胶-凝胶法制备了一系列TiO2、TiO2-Al2O3(TiAl)、MnO2/TiO2(MnTi)和MnO2/TiO2-Al2O3(MnTiAl)样品,在固定床实验装置上研究了MnTi和MnTiAl催化剂的脱硝、脱汞性能,并对相应的样品进行了BET、XRD、H2-TPR、XPS表征分析。表征结果表明,Al2O3掺入TiO2后能极大提高载体的比表面积,提升催化剂氧化还原性能,且有利于高价态锰离子(Mn^3+和Mn^4+)和化学吸附氧(O^*)在催化剂表面富集。固定床实验结果表明,在反应温度范围内,MnTiAl催化剂脱硝、脱汞性能均优于MnTi催化剂,MnTiAl催化剂在200℃时脱硝、脱汞效率分别高达88.5%和96.1%。MnTiAl脱除烟气Hg0过程中,将Hg0氧化为Hg^2+的同时,催化剂表面Mn^3+、Mn^4+和O^*浓度均被消耗,同时烟气中的O2能将催化剂表面较低价态的锰离子(Mn^2+和Mn^3+)重新氧化为高价态锰离子(Mn^3+和Mn^4+),并且能补充催化剂表面的化学吸附氧(O^*),进而实现催化剂催化氧化Hg0过程。
Sol-gel method was applied to synthesize TiO2,TiO2-Al2O3(TiAl),MnO2/TiO2(MnTi),and MnO2/TiO2-Al2O3(MnTiAl).The simultaneous removal of NO and Hg0 from the coal-fired flue gas over MnTi and MnTiAl catalysts were studied on a fixed-bed reactor system,and the corresponding samples were characterized and analyzed by BET,XRD,H2-TPR,and XPS.The characterization results showed that the introduction of Al2O3 into TiO2 could greatly increase the specific surface area of the support,improve the redox performance of the catalyst,and promote the enrichment of high-valence manganese ions(Mn^3+and Mn^4+)and chemisorbed oxygen(O*)on the catalyst surface.The results of the reaction experiments showed that the MnTiAl catalyst exhibited better NO and Hg0 removal performance than the MnTi catalyst in the entire reaction temperature range.The efficiencies of denitrification and mercury removal by MnTiAl catalyst at 200℃were as high as 88.5%and 96.1%,respectively,and the concentration of Mn^3+,Mn^4+,and O*on the surface of the catalyst were all consumed along with the oxidization of Hg0 to Hg^2+.At the same time,the O2 in the flue gas could re-oxidize the low-valence manganese ions(Mn^2+and Mn^3+)to high-valence manganese ions(Mn^3+and Mn^4+),as well as recover and replenish the chemically adsorbed oxygen(O^*)species on the surface of the catalyst,thereby realizing the catalytic Hg0 oxidation over the MnTiAl catalyst.
作者
董璐
黄亚继
丁守一
程好强
王圣
段钰锋
DONG Lu;HUANG Yaji;DING Shouyi;CHENG Haoqiang;WANG Sheng;DUAN Yufeng(Key Laboratory of Energy Thermal Conversion and Control of the Ministry of Education,Southeast University,Nanjing 210096,Jiangsu,China;State Power Environmental Protection Research Institute,Nanjing 210031,Jiangsu,China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2021年第1期234-241,共8页
Chemical Industry and Engineering Progress
基金
国家重点研发计划(2016YFC0201105)
江苏省研究生科研创新计划(KYCX17_0079)
东南大学优秀博士论文培育基金(3203009703)。
关键词
催化剂
煤燃烧
选择性催化还原
汞
二氧化钛
三氧化二铝
catalyst
coal combustion
selective catylitic reduction(SCR)
mercury
titanium dioxide(TiO2)
aluminum oxide(Al2O3)
