正在加载图片...
工程科学学报,第37卷,第8期:1049-1056,2015年8月 Chinese Journal of Engineering,Vol.37,No.8:1049-1056,August 2015 D0l:10.13374/j.issn2095-9389.2015.08.012:http://journals..ustb.edu.cn Cr-MnO./TiO2-Zr0,低温选择催化还原NO的活性及 抗毒性能 李哲”,汪莉2区,负丽”,王振南”,李梦霞”,李鑫” 1)北京科技大学土木与环境工程学院,北京1000832)北京科技大学金属矿山高效开采与安全教有部重点实验室,北京100083 ☒通信作者,E-mail:wangli(@cs.usth.cu.cm 摘要采用溶胶凝胶法制备TiO2一Z02载体,然后采用柠檬酸溶液浸渍法制备C-MnO,/TiO2一Z02复合催化剂.通过X 射线衍射、比表面积测试(BET)、扫描电镜、X射线光电子能谱等测试方法对催化剂的物化性能进行表征分析,并进行NH选 择性催化还原NO实验,考察催化剂在低温下的活性及抗硫抗水性能.Cr元素介入到MO,中,形成了新型的CrMn.,O活性 物相,其中的Mn元素多以Mn3·和Mn·存在.高价态的C+使Mn元素由Mn3·向高氧化态的Mn4·转化,有利于低温选择性 催化还原反应的进行.鉴于Cr元素第一电离能和电负性均低于Mn元素,能优先于Mn与SO~和SO~结合,保护MnO,不 被硫酸化,从而提高Cr-MnO,TiO2一ZO2催化剂的抗毒性能.制备的五种不同Cr/(Cr+Mn)摩尔比的催化剂中,Cr(0.4)- M0./Ti0,-Z0,的性能最优,其颗粒分散均匀,具有较大比表面积,在180℃时脱硝效率能够达到95.8%,同时通入5%H,0 和104S02,脱硝效率缓慢下降,反应8h后,下降到73%,并保持稳定. 关键词氧化物:催化剂:选择性催化还原:一氧化氮:活性 分类号X511 Activity and antitoxic properties of Cr-MnO /TiO,-ZrO,for low-temperature selective catalytic reduction of NO lZhe',WANG L2回,YUN Li,WANG Zhen-nan'',I Meng-xia',IXin” 1)School of Civil and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China 2)Key Laboratory of the Ministry of Education for High Efficient Mining and Safety in Metal Mines,University of Science and Technology Beijing,Bei- jing 100083,China Corresponding author,E-mail:wangli@ces.ustb.edu.cn ABSTRACT Using a sol-gel prepared TiO,-ZrO,carrier,Cr-MnO,/TiO,-ZrO,composite catalysts were synthesized by a critic acid solution impregnation method.The physical and chemical properties of the catalysts were characterized by X-ray diffraction, specific surface area determination (BET),scanning electron microscopy and X-ray photoelectron spectroscopy.Meanwhile,the low- temperature catalytic activity and the sulfur and water resistance were evaluated with selective catalytic reduction (SCR)of NO by NH3.The introduction of Cr element to MnO,yields a new CrMn.sO active phase,in which Mn primarily exists as Mn3and Mn. The Crvalence state facilitates the transformation of Mn to high oxidation state Mn',which is beneficial to the low temperature SCR reaction.Because of lower first ionization energy and electronegativity,Cr preferentially reacts with SOand SO than Mn, thus protecting MnO,not to be sulphatized and resulting in the enhanced antitoxic performance of Cr-MnO,/TiO,-Zr02.Among the prepared five catalysts with different molar ratios of Cr/(Cr Mn),Cr(0.4)-MnO,/TiO,-Zr02 demonstrates the best performance owing to the largest surface area and the best particle dispersion,and a 95.8%denitrification efficiency can be achieved at 180C. 收稿日期:2014-08-01 基金项目:科技部纳米重大科学研究计划资助项目(2013CB932600)工程科学学报,第 37 卷,第 8 期: 1049--1056,2015 年 8 月 Chinese Journal of Engineering,Vol. 37,No. 8: 1049--1056,August 2015 DOI: 10. 13374 /j. issn2095--9389. 2015. 08. 012; http: / /journals. ustb. edu. cn Cr--MnOx / TiO2 --ZrO2 低温选择催化还原 NO 的活性及 抗毒性能 李 哲1) ,汪 莉1,2) ,贠 丽1) ,王振南1) ,李梦霞1) ,李 鑫1) 1) 北京科技大学土木与环境工程学院,北京 100083 2) 北京科技大学金属矿山高效开采与安全教育部重点实验室,北京 100083  通信作者,E-mail: wangli@ ces. ustb. edu. cn 摘 要 采用溶胶凝胶法制备 TiO2 --ZrO2 载体,然后采用柠檬酸溶液浸渍法制备 Cr--MnOx /TiO2 --ZrO2 复合催化剂. 通过 X 射线衍射、比表面积测试( BET) 、扫描电镜、X 射线光电子能谱等测试方法对催化剂的物化性能进行表征分析,并进行 NH3 选 择性催化还原 NO 实验,考察催化剂在低温下的活性及抗硫抗水性能. Cr 元素介入到 MnOx 中,形成了新型的 CrMn1. 5O4 活性 物相,其中的 Mn 元素多以 Mn3 + 和 Mn4 + 存在. 高价态的 Cr5 + 使 Mn 元素由 Mn3 + 向高氧化态的 Mn4 + 转化,有利于低温选择性 催化还原反应的进行. 鉴于 Cr 元素第一电离能和电负性均低于 Mn 元素,能优先于 Mn 与 SO2 - 4 和 SO2 - 3 结合,保护 MnOx 不 被硫酸化,从而提高 Cr--MnOx /TiO2 --ZrO2 催化剂的抗毒性能. 制备的五种不同 Cr /( Cr + Mn) 摩尔比的催化剂中,Cr( 0. 4) -- MnOx /TiO2 --ZrO2 的性能最优,其颗粒分散均匀,具有较大比表面积,在180 ℃时脱硝效率能够达到 95. 8% ,同时通入 5% H2O 和 10 - 4 SO2,脱硝效率缓慢下降,反应 8 h 后,下降到 73% ,并保持稳定. 关键词 氧化物; 催化剂; 选择性催化还原; 一氧化氮; 活性 分类号 X511 收稿日期: 2014--08--01 基金项目: 科技部纳米重大科学研究计划资助项目( 2013CB932600) Activity and antitoxic properties of Cr--MnOx /TiO2 --ZrO2 for low-temperature selective catalytic reduction of NO LI Zhe1) ,WANG Li1,2)  ,YUN Li1) ,WANG Zhen-nan1) ,LI Meng-xia1) ,LI Xin1) 1) School of Civil and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China 2) Key Laboratory of the Ministry of Education for High Efficient Mining and Safety in Metal Mines,University of Science and Technology Beijing,Bei￾jing 100083,China  Corresponding author,E-mail: wangli@ ces. ustb. edu. cn ABSTRACT Using a sol-gel prepared TiO2 --ZrO2 carrier,Cr--MnOx /TiO2 --ZrO2 composite catalysts were synthesized by a critic acid solution impregnation method. The physical and chemical properties of the catalysts were characterized by X-ray diffraction, specific surface area determination ( BET) ,scanning electron microscopy and X-ray photoelectron spectroscopy. Meanwhile,the low￾temperature catalytic activity and the sulfur and water resistance were evaluated with selective catalytic reduction ( SCR) of NO by NH3. The introduction of Cr element to MnOx yields a new CrMn1. 5O4 active phase,in which Mn primarily exists as Mn3 + and Mn4 + . The Cr5 + valence state facilitates the transformation of Mn3 + to high oxidation state Mn4 + ,which is beneficial to the low temperature SCR reaction. Because of lower first ionization energy and electronegativity,Cr preferentially reacts with SO2 - 4 and SO2 - 3 than Mn, thus protecting MnOx not to be sulphatized and resulting in the enhanced antitoxic performance of Cr--MnOx /TiO2 --ZrO2 . Among the prepared five catalysts with different molar ratios of Cr /( Cr + Mn) ,Cr( 0. 4) --MnOx /TiO2 --ZrO2 demonstrates the best performance owing to the largest surface area and the best particle dispersion,and a 95. 8% denitrification efficiency can be achieved at 180 ℃ .
向下翻页>>
©2008-现在 cucdc.com 高等教育资讯网 版权所有