Molecular simulation study on the anti-As2O3 poisoning ability of γ-Fe2O3
ZHOU Wen-bo1, NIU Sheng-li1, LIU Si-tong1, WANG Dong2, HAN Kui-hua1, WANG Yong-zheng1
1. Shandong Engineering Laboratory for High-efficiency Energy Conservation and Energy Storage Technology & Equipment, School of Energy and Power Engineering, Shandong University, Jinan 250061, China; 2. Brook Byers Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta 30332, United States
Abstract：The γ-Fe2O3 catalyst, due to its advantages in low cost and high catalytic performance, is thought to be a promising medium-low temperature SCR catalyst, but the As2O3 in the flue gas likely becomes seriously deactivated. In this study, the density functional theory was used to characterize the adsorption of As2O3 on the γ-Fe2O3 surface as well as the mechanism of doping modification to improve the anti-As2O3 poisoning performance. The adsorption properties of As2O3 on the intact and O-deficient γ-Fe2O3(001) surfaces were examined, including adsorption site, adsorption structure, adsorption energy, PDOS, etc. At the same time, the catalyst model of γ-Fe2O3 doped with Mo, Ti, and Mg was established to understand the mechanism of doping additives on improving the resistance to arsenic poisoning. The results show that the As2O3 tends to be chemically adsorbed on Feoct sites on the γ-Fe2O3(001) surface with the O-terminus, and strong interaction and electron transfer occur during the adsorption process. When there are O defects on the surface, the adsorption energy of As2O3 molecules increases. Mo, Ti, and Mg tend to be doped in Feoct sites, which thus enhances the adsorption capacity of As2O3. Increasing the doping amount of Mo can promote the adsorption of As2O3. As2O3 tends to react with the more active Mo, Ti, and Mg, thereby protecting the active Fe sites from arsenic poisoning. The doping of Ti and Mg also inhibits the adsorption of As2O3 on adjacent Fe sites. The doping of Mo, Ti, and Mg also promotes the adsorption of NH3 on the catalyst surface and elevates the acidity of the surface, which is beneficial to the SCR reaction and to improving the anti-arsenic poisoning performance of the γ-Fe2O3 catalyst.
周文波, 牛胜利, 刘思彤, 王栋, 韩奎华, 王永征. γ-Fe2O3抗As2O3中毒能力的分子模拟[J]. 中国环境科学, 2022, 42(8): 3600-3609.
ZHOU Wen-bo, NIU Sheng-li, LIU Si-tong, WANG Dong, HAN Kui-hua, WANG Yong-zheng. Molecular simulation study on the anti-As2O3 poisoning ability of γ-Fe2O3. CHINA ENVIRONMENTAL SCIENCECE, 2022, 42(8): 3600-3609.
卞若愚,安忠义,李启超,等.O3-NH3协同活性焦脱硫脱硝的均相预反应特性研究[J]. 中国环境科学, 2021,41(10):4476-4483. Bian R U, An Z Y, Li Q C, et al. Characteristics of simultaneous removal of NOx and SO2by O3-NH3synergy.[J]. China Environmental Science, 2021,41(10):4476-4483.
Shi J, Zhang Z H, Chen M X, et al. Promotion effect of tungsten and iron co-addition on the catalytic performance of MnOx/TiO2 for NH3-SCR of NOx[J]. Fuel, 2017,210:783-789.
蒋春来,宋晓晖,钟悦之,等.2010~2015年中国燃煤电厂NOx排放特征[J]. 中国环境科学, 2018,38(8):2903-2910. Jiang C L, Song X H, Zhong Y Z, et al. Characteristics of NOx emissions from coal-fired power plants in China from 2010 to 2015[J]. China Environmental Science, 2018,38(8):2903-2910.
Li Y H, Deng J L, Song W Y, et al. Nature of Cu species in Cu-SAPO-18catalyst for NH3-SCR:Combination of experiments and DFT calculations[J]. The Journal of Physical Chemistry C, 2016, 120(27):14669-14680.
付金艳,王振峰,白心蕊,等.γ-Al2O3酸性修饰稀土尾矿NH3-SCR脱硝性能[J]. 中国环境科学, 2020,40(9):3741-3747. Fu J Y, Wang Z F, Bai X R, et al. Denitration performance of NH3-SCR from γ-Al2O3 acid modified rare earth tailings[J]. China Environmental Science, 2020,40(9):3741-3747.
刘晶,熊志波,周飞,等.新型铈钨钛复合氧化物催化还原脱硝机理[J]. 中国环境科学, 2018,38(5):1670-1676. Liu J, Xiong Z B, Zhou F, et al. The NH3-SCR mechanism of a novel cerium-tungsten-titanium mixed oxide catalyst prepared through the hydrothermal co-precipitation method modified by H2O2 complex[J]. China Environmental Science, 2018,38(5):1670-1676.
Chen H F, Xia Y, Huang H, et al. Highly dispersed surface active species of Mn/Ce/TiW catalysts for high performance at low temperature NH3-SCR[J]. Chemical Engineering Journal, 2017,330:1195-1202.
卿梦霞,刘亮,尹子骏,等.商用V/W/Ti系脱硝催化剂表面SO3生成的反应机理[J]. 中国环境科学, 2021,41(7):3161-3168. Qing M X, Liu L, Yin Z J, et al. Generation mechanism of SO3 on the surface of commercial V/W/Ti DeNOx catalysts[J]. China Environmental Science, 2021,41(7):3161-3168.
Liu C X, Yang S J, Ma L, et al. Comparison on the performance of α-Fe2O3 and γ-Fe2O3 for selective catalytic reduction of nitrogen oxides with ammonia[J]. Catalysis Letters, 2013,143(7):697-704.
张信莉,王栋,陈莲芳,等.Mn掺杂对磁性γ-Fe2O3低温SCR脱硝活性的影响[J]. 工程热物理学报, 2014,35:995-998. Zhang X L, Wang D, Chen L F et al. Influence of Mn doping on magnetic γ-Fe2O3 catalysts for selective catalytic reduction at low temperature[J]. Journal of Engineering Thermophysics, 2014,35:995-998.
Xu L T, Niu S L, Lu C M, et al. NH3-SCR performance and characterization over magnetic iron-magnesium mixed oxide catalysts[J]. Korean Journal of Chemical Engineering, 2017,34:1576-1583.
张月,王春波,刘慧敏,等.金属氧化物吸附剂干法脱除气相As2O3实验研究[J]. 燃料化学学报, 2015,43(4):476-482. Zhang Y, Wang C B, Liu H M et al. Removal of gas-phase As2O3 in dry process by metal oxide adsorbents[J]. Journal of Fuel Chemistry and Technology, 2015,43(4):476-482.
龚泓宇,胡红云,刘慧敏,等.燃煤过程中砷的迁移转化及控制技术综述[J]. 中国电机工程学报, 2020,40(22):15. Gong H Y, Hu H Y, Liu H M et al. Review of arsenic transformation and emission control during coal combustion[J]. Proceedings of the CSEE, 2020,40(22):15.
Ren S, Li S L, Su Z H, et al. Poisoning effects of KCl and As2O3 on selective catalytic reduction of NO with NH3over Mn-Ce/AC catalysts at low temperature[J]. Chemical Engineering Journal, 2018,351:540-547.
Li X, Li J H, Peng Y, et al. Regeneration of commercial SCR Catalysts:Probing the existing forms of arsenic oxide[J]. Environmental Science & Technology, 2015,49(16):9971-9978.
Peng Y, Li J H, Si W Z, et al. Insight into deactivation of commercial SCR catalyst by arsenic:An experiment and DFT study[J]. Environmental Science & Technology, 2014,48(23):13895-13900.
Li X Y, Chen J, Xiao Y, et al. Insight into the homogenous and heterogeneous transformation behavior of arsenic on commercial V2O5-WO3-TiO2 and novel γ-Fe2O3 catalysts during selective catalytic reduction of NOx[J]. Fuel, 2021,301:121051.
Peng Y, Si W Z, Li X, et al. Comparison of MoO3 and WO3 on arsenic poisoning V2O5/TiO2 catalyst:DRIFTS and DFT study[J]. Applied Catalysis B:Environmental, 2016,181:692-698.
Li X Y, Chen J, Lu C M, et al. Performance of Mo modified γ-Fe2O3 catalyst for selective catalytic reduction of NOx with ammonia:Presence of arsenic in flue gas[J]. Fuel, 2021,294:120552.
Li X Y, Chen J, Chen S Y, et al. Performance of Mg-Ti modified iron-based catalyst in NH3-SCR of NO at the presence of arsenic:Influence of oxygen and temperature[J]. Journal of Industrial and Engineering Chemistry, 2021,101:387-396.
Wu Y W, Zhou X Y, Mi T G, et al. Effect of WO3 and MoO3 doping on the interaction mechanism between arsenic oxide and V2O5-based SCR catalyst:A theoretical account[J]. Molecular Catalysis, 2021,499:111317.
Xing J Y, Wang C B, Si T, et al. Adsorption mechanism and competitive adsorption of As2O3 and NH3molecules on CuO(111) surface:a DFT study[J]. Journal of Molecular Modeling, 2021,27(6):178.
Hu P B, Weng Q Y, Li D L, et al. Research on the removal of As2O3 by γ-Al2O3 adsorption based on density functional theory[J]. Chemosphere, 2020,257:127243.
Jørgensen J E, Mosegaard L, Thomsen L E, et al. Formation of γ-Fe2O3 nanoparticles and vacancy ordering:An in situ X-ray powder diffraction study[J]. Journal of Solid State Chemistry, 2007,180(1):180-185.
Jian W, Wang S P, Zhang H X, et al. Disentangling the role of oxygen vacancies on the surface of Fe3O4 and γ-Fe2O3[J]. Inorganic Chemistry Frontiers, 2019,6(10):2660-2666.
Ren D D, Gui K T, Gu S C. Comparison of sulfur poisoning resistance of Ce/Mn doped γ-Fe2O3 (00 1) surface in NH3-SCR reaction with DFT method[J]. Applied Surface Science, 2021,561:149847.
Xie C Y, Sun Y L, Zhu B Z. The promoting mechanism of doping Mn, Co, and Ce on gas adsorption property and anti-SO2 oxidation over γ-Fe2O3 (001) surface:A density functional theory study[J]. Colloids and Surfaces A:Physicochemical and Engineering Aspects, 2021, 628:127218.
Guo P, Guo X, Zheng C G. Roles of γ-Fe2O3 in fly ash for mercury removal:Results of density functional theory study[J]. Applied Surface Science, 2010,256(23):6991-6996.
Segall M D, Lindan P J D, Probert M J, et al. First-principles simulation:ideas, illustrations and the CASTEP code[J]. Journal of Physics:Condensed Matter, 2002,14(11):2717-2744.
Song Z J, Wang B, Yu J, et al. Effect of Ti doping on heterogeneous oxidation of NO over Fe3O4(11 1) surface by H2O2:A density functional study[J]. Chemical Engineering Journal, 2018,354:517-524.
Zhang Y, Liu J. Density functional theory study of arsenic adsorption on the Fe2O3(001) surface[J]. Energy & Fuels, 2019,33(2):1414-1421.
Bentarcurt Y L, Calatayud M, Klapp J, et al. Periodic density functional theory study of maghemite (001) surface. Structure and electronic properties[J]. Surface Science, 2018,677:239-253.
Grau-Crespo R, Al-Baitai A Y, Saadoune I, et al. Vacancy ordering and electronic structure of γ-Fe2O3 (maghemite):a theoretical investigation[J]. Journal of Physics:Condensed Matter, 2010,22(25):255401.
Da Hora G C A, Longo R L, Da Silva J B P. Calculations of structures and reaction energy profiles of As2O3 and As4O6 species by quantum chemical methods[J]. International journal of quantum chemistry, 2012,112(20):3320-3324.
Lyu Z K, Niu S L, Lu C M, et al. A density functional theory study on the selective catalytic reduction of NO by NH3reactivity of α-Fe2O3 (00 1) catalyst doped by Mn, Ti, Cr and Ni[J]. Fuel, 2020,267:117147.
Maitarad P, Han J, Namuangruk S, et al. Theoretical guidance and experimental confirmation on catalytic tendency of M-CeO2 (M=Zr, Mn, Ru or Cu) for NH3-SCR of NO[J]. Molecular simulation, 2017,43(13-16):1240-1246.
杨涛,曹蕃,刘利军,等.掺杂Ce/Zr对γ-Al2O3(110)表面的影响[J]. 燃烧科学与技术, 2017,23(6):542-546. Yang T, Cao F, Liu L J et al. Impact of Ce/Zr Doping on γ-Al2O3(110) surface[J]. Journal of Combustion Science and Technology, 2017,23(6):542-546.
Ren D D, Gui K T. Study of the adsorption of NH3 and NOx on the nano-γFe2O3 (001) surface with density functional theory[J]. Applied Surface Science, 2019,487:171-179.
周文波,牛胜利,王栋,等.钛改性对γ-Fe2O3选择催化还原脱硝性能强化机制的分子模拟研究[J]. 燃料化学学报, 2020,48(10):1224-1235. Zhou W B, Niu S L, Wang D, et al. Promoting effect of Ti in the Ti-modified γ-Fe2O3catalyst on its performance in the selective catalytic reduction of NO with ammonia,a DFT calculation study[J]. Journal of Fuel Chemistry and Technology, 2020,48(10):1224-1235.
Li Z P, Niu S L, Han K H, et al. Investigation into influences of methanol pre-adsorption on CaO(100) surface in transesterification for biodiesel production with molecular simulation[J]. Applied Catalysis A:General, 2021,609:117908.
Li F F, Shi C M, Wang X F, et al. The important role of oxygen defect for NO gas-sensing behavior of α-Fe2O3 (00 1) surface:Predicted by density functional theory[J]. Computational Materials Science, 2018, 146:1-8.
Feng Y C, Wang N N, Guo X. Density functional theory study on improved reactivity of alkali-doped Fe2O3 oxygen carriers for chemical looping hydrogen production[J]. Fuel, 2019,236:1057-1064.
Zhang K H, Hu L T, Wang C F, et al. Middle-low-temperature oxidation and adsorption of arsenic from flue gas by Fe-Ce-based composite catalyst[J]. Chemosphere, 2022,288:132425.
Peng Y, Yu W W, Su W K, et al. An experimental and DFT study of the adsorption and oxidation of NH3 on a CeO2 catalyst modified by Fe, Mn, La and Y[J]. Catalysis Today, 2015,242:300-307.
Yang S J, Li J H, Wang C Z, et al. Fe-Ti spinel for the selective catalytic reduction of NO with NH3:Mechanism and structure-activity relationship[J]. Applied Catalysis B:Environmental, 2012,117-118:73-80.
Man I C, Soriga S G, Parvulescu V. Effect of Ca and Sr in MgO(100) on the activation of methanol and methyl acetate[J]. Catalysis Today, 2018,306:207-214.