金属Sr、Fe掺杂对LaCoO3催化氧化碳烟及抗硫性能影响
Effect of Sr and Fe Doped LaCoO3 on Catalytic Oxidation of Soot and Sulfur Resistance
作者单位E-mail
魏炜 广州大学化学化工学院, 能源与催化研究所, 广州 510006  
吴艾纯 广州大学化学化工学院, 能源与催化研究所, 广州 510006  
乔智威 广州大学化学化工学院, 能源与催化研究所, 广州 510006  
李树华 广州大学化学化工学院, 能源与催化研究所, 广州 510006  
梁红 广州大学化学化工学院, 能源与催化研究所, 广州 510006 lhong@gzhu.edu.cn 
彭峰 广州大学化学化工学院, 能源与催化研究所, 广州 510006 fpeng@gzhu.edu.cn 
摘要: 利用柠檬酸-EDTA(乙二胺四乙酸)配位法制备了La1-xSrxCo1-yFeyO3催化剂,展现出较好的催化氧化碳烟(soot)活性和抗硫性能。通过X射线衍射(XRD)、傅利叶红外光谱(FT-IR)、扫描电镜(SEM)、H2-程序升温还原(H2-TPR)、X射线光电子能谱(XPS)和SO2程序升温脱附(SO2-TPD)等研究了Sr、Fe掺杂对催化剂物理化学性质及抗硫能力影响。当Sr掺杂LaCoO3时有利于形成较多的表面吸附氧(O2-、O-)和氧空位,且低温氧化还原性能亦有较大改善,提高了催化氧化碳烟活性,其Ti(起燃温度)和Tm(最大碳烟燃烧速率温度)分别为284和347℃。当催化剂同时掺杂Sr、Fe时,其低温氧化还原性能进一步改善,并形成较多Fe4+离子,有利于提高催化氧化碳烟活性。催化剂SO2中毒失活主要来源于Co2+/Co3+和表面吸附氧的硫酸化(SO32-、SO42-)。XPS和SO2-TPD结果表明,LaSrCoFeO3抗硫性主要来源于Fe3+与SO2结合形成的硫酸盐物种,降低了SO2对活性组分表面吸附氧和Fe4+毒化。TPO(程序升温氧化)结果表明,硫化后的LaSrCoFeO3-S仍具有较好的催化氧化碳烟活性,其Tm仅为361℃,表明Sr、Fe同时掺杂具有较好的低温催化氧化碳烟活性和良好的抗硫性能。
关键词: 催化氧化  抗硫  掺杂  移动源  钙钛矿  碳烟
基金项目: 国家自然科学基金(No.21576058)资助项目
Abstract: A series of perovskite-type La1-xSrxCo1-yFeyO3 catalysts were successfully prepared by the citric acid-EDTA complexation. The catalysts exhibited excellent catalytic oxidation soot activity and sulfur resistance. The characterization of X-ray diffraction (XRD), fourier transform infrared spectra (FT-IR), scanning electron microscope (SEM), H2-temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS) and SO2-temperature programmed desorption (SO2-TPD) were used to reveal the effect of Sr and Fe doping on the physicochemical properties and sulfur tolerance of La1-xSrxCo1-yFeyO3 catalysts. Experimental results demonstrated that when the Sr doped with LaCoO3, it was beneficial for the catalyst to form more surface adsorption oxygen (O2- or O-) and oxygen vacancies, thereby improving both the low-temperature redox ability and catalytic oxidation soot activity of catalyst. Ti (ignition temperature of soot) and Tm (complete conversion temperature of soot) are only 284 and 347℃. Furthermore, with the doping of Fe, the low-temperature redox performance of catalyst was further improved, because the high-valent ions (Fe4+) were formed in the surface of catalyst, the Fe4+ ion could enhance the oxidation soot activity of catalyst. Moreover, the poisoning of SO2 was mainly attributed to the sulfation (SO32-, SO42-) of Co2+/Co3+ and surface adsorbed oxygen, leading to deactivating the active site (O2- or O- and Fe4+) of catalyst. Simultaneous doping of Sr and Fe can form a strong interaction, which can effectively inhibit the deposition of sulfur species on the catalyst surface and reduce the poisoning of SO2 into the catalyst. Both XPS and SO2-TPD characterizations showed that the sulfur resistance of catalyst was mainly attributed the competitive adsorption of metal ions (Fe3+) on SO2, which could effectively reduce the poisoning of SO2 on the surface adsorption oxygen and Fe4+. TPO (temperature programmed oxidation) activity characterization showed that LaSrCoFeO3-S still maintained good catalytic oxidation soot activity. Ti and Tm were 320 and 361℃, respectively, indicating that the simultaneous doping of Sr and Fe has excellent low-temperature catalytic soot activity and good sulfur poisoning ability.
Keywords: catalytic oxidation  sulfur resistance  doping  mobile source  perovskite  soot
投稿时间:2019-06-23 修订日期:2019-12-05
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魏炜,吴艾纯,乔智威,李树华,梁红,彭峰.金属Sr、Fe掺杂对LaCoO3催化氧化碳烟及抗硫性能影响[J].无机化学学报,2020,36(1):87-96.
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